List of plant genera named for people (Q–Z)
# List of plant genera named for people (Q–Z)

Since the first printing of Carl Linnaeus's Species Plantarum in 1753, plants have been assigned one epithet or name for their species and one name for their genus, a grouping of related species. Thousands of plants have been named for people, including botanists and their colleagues, plant collectors, horticulturists, explorers, rulers, politicians, clerics, doctors, philosophers and scientists. Even before Linnaeus, botanists such as Joseph Pitton de Tournefort, Charles Plumier and Pier Antonio Micheli were naming plants for people, sometimes in gratitude for the financial support of their patrons.

Early works researching the naming of plant genera include an 1810 glossary by Alexandre de Théis [fr] and an etymological dictionary in two editions (1853 and 1856) by Georg Christian Wittstein. Modern works include The Gardener's Botanical by Ross Bayton, Index of Eponymic Plant Names and Encyclopedia of Eponymic Plant Names by Lotte Burkhardt, Plants of the World by Maarten J. M. Christenhusz (lead author), Michael F. Fay and Mark W. Chase, The A to Z of Plant Names by Allan J. Coombes, the four-volume CRC World Dictionary of Plant Names by Umberto Quattrocchi, and Stearn's Dictionary of Plant Names for Gardeners by William T. Stearn; these supply the seed-bearing genera listed in the first column below. Excluded from this list are genus names not accepted (as of January 2021) at Plants of the World Online, which includes updates to Plants of the World (2017).

## Key

    Ba = listed in Bayton's The Gardener's Botanical
    Bt = listed in Burkhardt's Encyclopedia of Eponymic Plant Names
    Bu = listed in Burkhardt's Index of Eponymic Plant Names
    Ch = listed in Christenhusz's Plants of the World
    Co = listed in Coombes's The A to Z of Plant Names
    Qu = listed in Quattrocchi's CRC World Dictionary of Plant Names
    St = listed in Stearn's Dictionary of Plant Names for Gardeners

In addition, Burkhardt's Index is used as a reference for every row in the table.

## Genera

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z

Genera :

| Genus | Person honored | Plant family | Ref |
| - | - | - | - |
| Quassia | Graman Quassi (c. 1690 – c. 1780) | Simaroubaceae | St |
| Quekettia | Edwin John Quekett (1808–1847) | Orchidaceae | Bu |
| Quelchia | John Joseph Quelch (1854–1939?), collector of plants in Guyana | Asteraceae | Bu |
| Quesnelia | Edouard Prosper Quesnel (1781–1850), cotton and shipping merchant | Bromeliaceae | Bu |
| Quezeliantha | Pierre Ambrunaz Quézel (1926–2015), French doctor, botanist and ecologist | Brassicaceae | Bu |
| Quinetia | Edgar Quinet (1803–1875), historian | Asteraceae | Bu |
| Quintinia | Jean-Baptiste de La Quintinie (1626–1688) | Paracryphiaceae | Bu |
| Quoya | Jean René Constant Quoy (1790–1869) | Lamiaceae | Bu |
| Rabiea | William Abbot Rabie (1869–1936), South African clergyman and plant collector | Aizoaceae | Bu |
| Rachelia | Rachel Chisholm, born Kevern (1915–2017), New Zealand farmer at Molesworth Station | Asteraceae | Bu |
| Racinaea | Racine Sarasy Foster (1910–1991), plant collector in Central and South America with her husband Mulford B. Foster | Bromeliaceae | Bu |
| Radcliffea | Alan Radcliffe-Smith (1938–2007), English curator for Euphorbiaceae at the Kew Gardens herbarium | Euphorbiaceae | Bu |
| Raddia | Giuseppe Raddi (1770–1829) | Poaceae | Qu |
| Raddiella | Giuseppe Raddi (1770–1829) | Poaceae | Qu |
| Radermachera | Jacob Cornelis Matthieu Radermacher (1741–1783) | Bignoniaceae | Ba |
| Radlkofera | Ludwig Adolph Timotheus Radlkofer (1829–1927) | Sapindaceae | Bu |
| Radlkoferotoma | Ludwig Adolph Timotheus Radlkofer (1829–1927) | Asteraceae | Bu |
| Radyera | Robert Allen Dyer (1900–1987) | Malvaceae | Bu |
| Raffenaldia | Alire Raffeneau Delile (1778–1850) | Brassicaceae | St |
| Rafflesia | Stamford Raffles (1781–1826) | Rafflesiaceae | Ch |
| Rafinesquia | Constantine Samuel Rafinesque (1783–1840) | Asteraceae | Bu |
| Rafnia | Carl Gottlob Rafn (1769–1808) | Fabaceae | Bu |
| Raillardella | Laurent Railliard or Raillard (1792–1845), French naval officer; introduced to botany by Charles Gaudichaud-Beaupré | Asteraceae | Bu |
| Raimondia | Antonio Raimondi (1826–1890) | Annonaceae | Bu |
| Rainiera | Peter Rainier (1741–1808), Royal Navy officer | Asteraceae | Bt |
| Ramirezella | José Aurelio Ramirez Mateos (1852–1904), Mexican doctor, botanist and zoologist | Fabaceae | Bu |
| Ramonda | Louis Ramond de Carbonnières (1755–1827) | Gesneriaceae | Co |
| Ramonadoxa | Ramona Oviedo Prieto (b.1953), Cuban botanist and agriculturist, who worked at the Institute of Ecology and Systematics (Cuban Academy of Sciences) | Rubiaceae | Bt |
| Ramorinoa | Juan Ramorino (1840–1876), Italian botanist and paleontologist; professor of natural science and mineralogy | Fabaceae | Bu |
| Ramosmania | Raman Osman (1902–1992), governor-general | Rubiaceae | Bu |
| Randia | Isaac Rand (1674–1743) | Rubiaceae | St |
| Randonia | Jacques Louis Randon (1795–1871), colonial administrator | Resedaceae | Bu |
| Ranzania | Ono Ranzan (1729–1810) | Berberidaceae | St |
| Raoulia | Étienne Raoul (1815–1852) | Asteraceae | St |
| Raouliopsis | Étienne Raoul (1815–1852) | Asteraceae | Bu |
| Ratzeburgia | Julius Theodor Christian Ratzeburg (1801–1871) | Poaceae | Bu |
| Rauhia | Werner Rauh (1913–2000) | Amaryllidaceae | Qu |
| Rauhiella | Werner Rauh (1913–2000) | Orchidaceae | Qu |
| Rauhocereus | Werner Rauh (1913–2000) | Cactaceae | Qu |
| Rauia | Ambrosius Rau (1784–1830), German botanist and mineralogist; professor of natural history and forestry | Rutaceae | Bu |
| Raulinoa | Raulino Reitz (1919–1990), Brazilian clergyman, historian, botanist, and botanical garden director | Rutaceae | Bu |
| Raulinoreitzia | Raulino Reitz (1919–1990), Brazilian clergyman, historian, botanist, and botanical garden director | Asteraceae | Bu |
| Rauvolfia | Leonhard Rauwolf (c. 1537 – 1596) | Apocynaceae | St |
| Ravenea | Louis Fréderic Jacques Ravené (1823–1879), official in Berlin | Arecaceae | Qu |
| Ravenia | Jean François Ravin (18th century), French doctor, professor of botany and medicine at the University of Coimbra in Portugal | Rutaceae | Bu |
| Raveniopsis | Jean François Ravin (18th century), French doctor, professor of botany and medicine at the University of Coimbra in Portugal | Rutaceae | Bu |
| Rawsonia | Rawson W. Rawson (1812–1899), colonial administrator | Achariaceae | Bu |
| Rayjacksonia | Raymond Carl Jackson (1928–2008) | Asteraceae | Bu |
| Razafimandimbisonia | Sylvaen Georges Razafimandimbison (b. 1964), botanist from Madagascar | Rubiaceae | Bu |
| Reaumuria | René Antoine Ferchault de Réaumur (1683–1757) | Tamaricaceae | Bu |
| Rebutia | Pierre Rebut (1827–1902) | Cactaceae | St |
| Recchia | Nardo Antonio Recchi (1540–1595), Italian royal personal physician | Simaroubaceae | Bu |
| Recordia | Samuel J. Record (1881–1945) | Verbenaceae | Bu |
| Recordoxylon | Samuel J. Record (1881–1945) | Fabaceae | Bu |
| Reedia | Joseph Reed (c. 1823 – 1890), architect | Cyperaceae | Bu |
| Reevesia | John Reeves (1774–1856) | Malvaceae | Bu |
| Regnellidium | Anders Fredrik Regnell (1807–1884) | Marsileaceae | Bt |
| Rehdera | Alfred Rehder (1863–1949) | Verbenaceae | Qu |
| Rehderodendron | Alfred Rehder (1863–1949) | Styracaceae | Ba |
| Rehia | Richard Eric Holttum (1895–1990) | Poaceae | Bu |
| Rehmannia | Joseph Rehmann (1779–1831), physician in Saint Petersburg | Orobanchaceae | Co |
| Reichardia | Johann Jacob Reichard (1743–1782) | Asteraceae | Bu |
| Reicheella | Karl Friedrich Reiche (1860–1929) | Caryophyllaceae | Bu |
| Reichenbachia | Ludwig Reichenbach (1793–1879) | Nyctaginaceae | Bu |
| Reicheocactus | Karl Friedrich Reiche (1860–1929) | Cactaceae | Bt |
| Reineckea | Johann Heinrich Julius Reinecke (1799–1871), German horticulturist | Asparagaceae | Ba |
| Reinhardtia | Johannes Theodor Reinhardt (1816–1882) | Arecaceae | Bu |
| Reinwardtia | Caspar Georg Carl Reinwardt (1773–1854) | Linaceae | St |
| Reinwardtiodendron | Caspar Georg Carl Reinwardt (1773–1854) | Meliaceae | Bu |
| Reissantia | Charles Tisserant (1886–1962), French clergyman, botanist and plant collector | Celastraceae | Bu |
| Reissekia | Siegfried Reissek (1819–1871) | Rhamnaceae | Bu |
| Reitzia | Raulino Reitz (1919–1990), Brazilian clergyman, historian, botanist, and botanical garden director | Poaceae | Bu |
| Relchela | Willibald Lechler (1814–1856), German apothecary, botanist and explorer | Poaceae | Bu |
| Reldia | Robert Louis Dressler (b. 1927) | Gesneriaceae | Bu |
| Remijia | Remijo or Remigio, Brazilian doctor who wrote about the uses of Cinchona bark | Rubiaceae | Bu |
| Remusatia | Jean-Pierre Abel-Rémusat (1788–1832), sinologist | Araceae | St |
| Remya | Jules Rémy (1826–1893) | Asteraceae | Bu |
| Renealmia | Paul Reneaulme (1560–1624), French physician and botanical author | Zingiberaceae | St |
| Rennellia | James Rennell (1742–1830) | Rubiaceae | Bu |
| Renschia | Carl Wilhelm Rensch (1837–1905), German teacher in Berlin | Lamiaceae | Bu |
| Rensonia | Carlos Renson (1858–1941), Belgian apothecary who collected plants in San Salvador, El Salvador | Asteraceae | Bu |
| Renvoizea | Stephen Andrew Renvoize (b. 1944), English botanist who worked at Kew Gardens, specialist in grasses | Poaceae | Bu |
| Requienia | Esprit Requien (1788–1851) | Fabaceae | Bu |
| Resia | Richard Evans Schultes (1915–2001) | Gesneriaceae | Bu |
| Restella | Georg Wilhelm Steller (1709–1746) | Thymelaeaceae | Bu |
| Restrepia | José Manuel Restrepo Vélez (1781–1863) | Orchidaceae | Qu |
| Restrepiella | José Manuel Restrepo Vélez (1781–1863) | Orchidaceae | Qu |
| Reyesia | Antonio García Reyes (1817–1855), Chilean botanist; university professor in Chile | Solanaceae | Bu |
| Reynaudia | Auguste Adolphe Marc Reynaud (1804–1867) | Poaceae | Bu |
| Reynosia | Alvaro Francisco Carlos Reynoso y Valdés (1829–1888), Cuban agronomist and chemist in Havana | Rhamnaceae | Bu |
| Reynoutria | Karel van Sint-Omaars (c. 1532 – 1569), Lord of Dranouter, Flemish botanist | Polygonaceae | St |
| Rhazya | Muhammad ibn Zakariya al-Razi (10th century) | Apocynaceae | St |
| Rhodosciadium | Joseph Nelson Rose (1862–1928) | Apiaceae | Bu |
| Rhodoscirpus | Encarnación Rosa Guaglianone (1932–2014), Argentinian botanist; specialist in Cyperaceae | Cyperaceae | Bu |
| Richardia | Richard Richardson (1663–1741) | Rubiaceae | St |
| Richardsiella | Mary Alice Eleanor Richards (1895–1977) | Poaceae | Bu |
| Richea | Claude Riche (1762–1797) | Ericaceae | St |
| Richeria | Pierre Richer de Belleval (c. 1564 – 1632) | Phyllanthaceae | Bu |
| Richterago | Hermann Eberhard Friedrich Richter (1808–1876), German doctor, botanist and professor in Dresden | Asteraceae | Bu |
| Richteria | Alexander Vilgelmovich Richter (1804–1849), director of the Moscow University Library in Russia | Asteraceae | Bu |
| Ricotia | Paul Rycaut (1628–1700), diplomat | Brassicaceae | Bu |
| Ridleyandra | Henry Nicholas Ridley (1855–1956) | Gesneriaceae | Bu |
| Ridleyella | Henry Nicholas Ridley (1855–1956) | Orchidaceae | Bu |
| Ridolfia | Cosimo Ridolfi (1794–1865), Italian nobleman, politician and agronomist | Apiaceae | Bu |
| Ridsdalea | Colin Ernest Ridsdale (1944–2017), English botanist, Specialist in tropical plants and Rubiaceae family | Rubiaceae | Bt |
| Riedelia | Johann Gerard Friedrich Riedel (1832–1911); served with the Dutch East India Company and collected plants | Zingiberaceae | Bu |
| Riedeliella | Ludwig Riedel (1790–1861) | Fabaceae | Bu |
| Riencourtia | Cathérine Elisabeth Agathe Cassini, born de Riencourt (1783–1861), wife of Henri Cassini | Asteraceae | Bu |
| Rindera | Franz Andreas Rinder (1714–1772), German-born Russian doctor in Orenburg and Moscow who discovered this plant in the Ural Mountains | Boraginaceae | Bu |
| Rinzia | Sebastian Rinz (1782–1861) and his son Jacob Rinz (1809–1860), both German gardeners for the city of Frankfurt | Myrtaceae | Qu |
| Riocreuxia | Alfred Riocreux (1820–1912) | Apocynaceae | Bu |
| Riqueuria | Ludovico Riqueur (d. 1737), court apothecary during the time of Philip V of Spain; cultivator of exotic trees | Rubiaceae | Bu |
| Risleya | Herbert Hope Risley (1851–1911), colonial administrator | Orchidaceae | Bu |
| Ristantia | Jules Marie Claude de Tristan (1776–1861), French botanist and botanical garden administrator in Orléans | Myrtaceae | Bu |
| Ritchiea | Joseph Ritchie (c. 1788 – 1819) | Capparaceae | Bu |
| Rivasgodaya | Salvador Rivas Goday (1905–1981), Spanish botanist and plant geographer, professor of pharmacy in Madrid | Fabaceae | Bu |
| Rivasmartinezia | Salvador Rivas Martínez (1935–2020), Spanish Biologist, Apothecary, Botanist (Mycology, Lichenology, Pteridology), also mountaineer and Alpinist, | Apiaceae | Bt |
| Rivea | Auguste Arthur de la Rive (1801–1873) | Convolvulaceae | Bu |
| Rivina | Augustus Quirinus Rivinus (1652–1723) | Phytolaccaceae | St |
| Robbrechtia | Elmar Robbrecht (b. 1946), Belgian botanist and mycologist at the national botanic gardens; specialist in Rubiaceae | Rubiaceae | Bu |
| Robinia | Jean Robin (1550–1629) | Fabaceae | Co |
| Robinsonecio | Harold E. Robinson (1932–2020) | Asteraceae | Bu |
| Robinsonella | Benjamin Lincoln Robinson (1864–1935) | Malvaceae | Bu |
| Robiquetia | Pierre Jean Robiquet (1780–1840) | Orchidaceae | Bu |
| Robsonodendron | Norman K. B. Robson (1928–2021) | Celastraceae | Bu |
| Robynsia | Frans Hubert Edouard Arthur Walter Robyns (1901–1986) | Rubiaceae | Bu |
| Robynsiophyton | Frans Hubert Edouard Arthur Walter Robyns (1901–1986) | Fabaceae | Bu |
| Rochefortia | Charles de Rochefort (1605–1683), French clergyman who explored the Antilles | Boraginaceae | Bu |
| Rochelia | Anton Rochel (1770–1847) | Boraginaceae | Bu |
| Rochonia | Alexis-Marie de Rochon (1741–1817), physicist | Asteraceae | Bu |
| Rockia | Joseph Rock (1884–1962) | Nyctaginaceae | Bu |
| Rodgersia | John Rodgers (1812–1882), admiral | Saxifragaceae | Co |
| Rodriguezia | Manuel or Emmanuel Rodríguez (18th century) | Orchidaceae | St |
| Roella | Wilhelm Roell (1700–1775), Dutch horticulturist and professor of anatomy | Campanulaceae | Qu |
| Roepera | Johannes August Christian Roeper (1801–1885), German doctor and professor of botany in Basel and Rostock | Zygophyllaceae | Qu |
| Roeperocharis | Johannes August Christian Roeper (1801–1885), German doctor and professor of botany in Basel and Rostock | Orchidaceae | Qu |
| Rogeria | Jacques-François Roger (1787–1849), French lawyer, colonial administrator, plant collector | Pedaliaceae | Bu |
| Rogersonanthus | Clark Thomas Rogerson (1918–2001) | Gentianaceae | Bu |
| Rogiera | Charles Rogier (1800–1885), statesman | Rubiaceae | Bu |
| Rohdea | Michael Rohde (1782–1812) | Asparagaceae | Co |
| Roifia | Adriano Fiori (1865–1950) | Malvaceae | Bu |
| Roigella | Juan Tomás Roig (1877–1971), Cuban teacher and botanist in Havana | Rubiaceae | Bu |
| Rojasia | Teodoro Rojas (1877–1954) | Apocynaceae | Bu |
| Rojasianthe | Ulises Rojas Bendfeldt (1881–1959), professor of botany and botanical garden director in Guatemala | Asteraceae | Bu |
| Rojasimalva | Carmen Emilia Benítez de Rojas (b. 1937), Venezuelan botanist, university professor; specialist in Solanaceae | Malvaceae | Bu |
| Rokautskyia | Roberto Anselmo Kautsky (1924–2010), Brazilian botanist | Bromeliaceae | Bt |
| Rolandra | Daniel Rolander (1725–1793) | Asteraceae | Bu |
| Roldana | Eugenio Montaña y Roldán (1778–1813), Otumban fighter in Mexico's war of independence | Asteraceae | Bu |
| Romanoa | Girolamo Romano (1765–1841), Italian clergyman and botanist from Padua | Euphorbiaceae | Bu |
| Romanschulzia | Roman Schulz (1873–1926), German botanist and teacher in Berlin | Brassicaceae | Bu |
| Romanzoffia | Nikolay Rumyantsev (1754–1826), diplomat | Hydrophyllaceae | Qu |
| Romeroa | Rafael Romero-Castañeda (1910–1973), Colombian botanist | Bignoniaceae | Bu |
| Romneya | Thomas Romney Robinson (1792–1882), astronomer | Papaveraceae | Co |
| Rondeletia | Guillaume Rondelet (1507–1566) | Rubiaceae | St |
| Rondonanthus | Cândido Rondon (1865–1958), military officer | Eriocaulaceae | Bu |
| Ronnbergia | Auguste Ronnberg (1813–1888), Belgian director of agriculture | Bromeliaceae | Bu |
| Roscheria | Albrecht Roscher (1836–1860) | Arecaceae | Bu |
| Roscoea | William Roscoe (1753–1831) | Zingiberaceae | Co |
| Rosenbergiodendron | Gustaf Otto Rosenberg (1872–1948) | Rubiaceae | Bu |
| Roseodendron | Joseph Nelson Rose (1862–1928) | Bignoniaceae | Bu |
| Rosselia | Elisabeth Paul Eduard de Rossel (1765–1829), French astronomer and Master-at-arms | Burseraceae | Bt |
| Rossioglossum | John Ross (fl. 1830–1840), collector of orchids in Oaxaca, Mexico | Orchidaceae | Qu |
| Rostkovia | Friedrich Wilhelm Gottlieb Rostkovius (1770–1848) | Juncaceae | Bu |
| Rothia | Albrecht Wilhelm Roth (1757–1834) | Fabaceae | Bu |
| Rothmaleria | Werner Rothmaler (1908–1962) | Asteraceae | Qu |
| Rothmannia | Göran Rothman (1739–1778) | Rubiaceae | Ba |
| Rottboellia | Christen Friis Rottbøll (1727–1797) | Poaceae | Bu |
| Roucheria | Jean-Antoine Roucher (1745–1794), poet | Linaceae | Qu |
| Roussea | Jean-Jacques Rousseau (1712–1778), Enlightenment philosopher | Rousseaceae | Bu |
| Rousseauxia | Louis Auguste Joseph Desrousseaux (1753–1838) | Melastomataceae | Bu |
| Rousselia | perhaps Henri François Anne de Roussel (1748–1812) or Alexandre Victor Roussel (1795–1874), French military apothecary and botanist | Urticaceae | Bu |
| Rovaeanthus | Johan H. E. Rova (fl. 1990–2002), Swedish botanist at the University of Gothenburg | Rubiaceae | Bu |
| Roycea | Robert Royce (1914–2008) | Amaranthaceae | Bu |
| Roylea | John Forbes Royle (1799–1858) | Lamiaceae | Bu |
| Roystonea | Roy Stone (1836–1905), military officer and engineer | Arecaceae | St |
| Rudbeckia | Olaus Rudbeck (1630–1702) and his son Olof Rudbeck the Younger (1660–1740) | Asteraceae | Co |
| Rudgea | Edward Rudge (1763–1846) | Rubiaceae | Bu |
| Ruehssia | Carl Andreas Rühsz (1805–1880), German consul in Puerto Cabello, Venezuela; supporter of art and science | Apocynaceae | Bu |
| Ruellia | Jean Ruel (1474–1537) | Acanthaceae | St |
| Ruelliopsis | Jean Ruel (1474–1537) | Acanthaceae | Bu |
| Rugelia | Ferdinand Ignatius Xavier Rugel (1806–1879), German-born American apothecary, doctor and botanist | Asteraceae | Bu |
| Rugoloa | Sulma (Zulma) E. Rúgolo de Agrasar (b.1940), who was an Argentinian botanist, Curator and Professor at the National University of La Pampa | Poaceae | Bt |
| Ruhooglandia | Ruurd Dirk Hoogland (1922–1994) | Poaceae | Bt |
| Ruilopezia | Luis Enrique Ruíz-Terán (1923–1979) and Manuel López-Figueiras (1915–2012), Venezuelan botanists and plant collectors | Asteraceae | Bu |
| Ruizia | Hipólito Ruiz López (1754–1815) | Malvaceae | Bu |
| Ruizodendron | Hipólito Ruiz López (1754–1815) | Annonaceae | Bu |
| Ruizterania | Luis Enrique Ruíz-Terán (1923–1979), Venezuelan researcher and university professor of botany | Vochysiaceae | Bu |
| Rumfordia | Benjamin Thompson (1753–1814), physicist and inventor | Asteraceae | Bu |
| Rungia | Friedlieb Ferdinand Runge (1794–1867) | Acanthaceae | Bu |
| Rupertia | Rupert Charles Barneby (1911–2000) | Fabaceae | Bu |
| Ruppia | Heinrich Bernhard Ruppius (1688–1719) | Ruppiaceae | Qu |
| Ruprechtia | Franz Josef Ruprecht (1814–1870) | Polygonaceae | Qu |
| Rusbya | Henry Hurd Rusby (1855–1940) | Ericaceae | Bu |
| Ruschia | Ernst Julius Rusch (1867–1957), South African farmer and collector | Aizoaceae | St |
| Ruschianthus | Ernst Franz Theodor Rusch (1897–1964), German-Namibian amateur botanist who collected and cultivated succulents | Aizoaceae | Bu |
| Ruspolia | Eugenio Ruspoli (1866–1893) | Acanthaceae | St |
| Russelia | Alexander Russell (1715–1768) | Plantaginaceae | Co |
| Russowia | Edmund Russow (1841–1897) | Asteraceae | Bu |
| Rustia | Johann Nepomuk Rust (1775–1840), doctor | Rubiaceae | Bu |
| Rutheopsis | Johann Friedrich Ruthe (1788–1859) | Apiaceae | Bu |
| Ruthiella | Ruth van Crevel (b. 1926), Dutch botanical photographer and illustrator | Campanulaceae | Bu |
| Ruttya | John Rutty (1697–1775) | Acanthaceae | St |
| Ruyschia | Frederik Ruysch (1638–1731) | Marcgraviaceae | Bu |
| Ryania | John Ryan (d. c. 1804), English doctor who collected plants from Brazil to the Caribbean | Salicaceae | Bu |
| Rydingia | Per Olof Ryding (b.1951), Swedish botanist and plant collector in Africa | Lamiaceae | Bt |
| Rzedowskia | Jerzy Rzedowski (b. 1926) | Celastraceae | Bu |
| Sabatia | Liberato Sabbati (b. 1714), Italian botanist | Gentianaceae | St |
| Sabinaria | Sabina Bernal Galeano (b.1995), daughter of the botanical authors, Gloria Galeano and Rodrigo Bernal | Arecaceae | Bt |
| Sachsia | Julius von Sachs (1832–1897) | Asteraceae | Bu |
| Sacleuxia | Charles Sacleux (1856–1943) | Apocynaceae | Bu |
| Sageretia | Augustin Sageret (1763–1851) | Rhamnaceae | Ba |
| Sagotia | Paul Antoine Sagot (1821–1888), French naval doctor, botanist and plant collector; also worked for the National Museum of Natural History | Euphorbiaceae | Bu |
| Sagraea | Ramón de la Sagra (1798–1871) | Melastomataceae | Bu |
| Saintpauliopsis | Walter Le Tanneux de Saint Paul-Illaire (1860–1940), German imperial precinct captain in German East Africa (roughly present-day Tanzania), and his father, Ulrich Maximilian von Saint Paul-Illaire (1833–1902), German naval officer and court official | Acanthaceae | Qu |
| Salmea | Joseph zu Salm-Reifferscheidt-Dyck (1773–1861) | Asteraceae | Qu |
| Salmonopuntia | Joseph zu Salm-Reifferscheidt-Dyck (1773–1861) | Cactaceae | Bt |
| Salomonia | Solomon (1033 BC – 975 BC), king | Polygalaceae | Bu |
| Saltia | Henry Salt (1780–1827), artist and traveller | Amaranthaceae | Bu |
| Saltugilia | Filippo Luigi Gilii (1756–1821), Italian clergyman, naturalist and astronomer from the Vatican City | Polemoniaceae | Bt |
| Salvadora | Jaime Salvador y Pedrol (1649–1740), Spanish apothecary in Barcelona; collected plants in Catalonia | Salvadoraceae | Bu |
| Salvadoropsis | Jaime Salvador y Pedrol (1649–1740), Spanish apothecary in Barcelona; collected plants in Catalonia | Celastraceae | Bu |
| Salvertia | Augustin Amable Dutour de Salvert or Du Tour de Salvert Bellenave (1781–1838), French botanist and writer, brother-in-law of the author of the genus, Augustin Saint-Hilaire | Vochysiaceae | Bu |
| Salzmannia | Philipp Salzmann (1781–1851), German doctor, botanist and entomologist | Rubiaceae | Bu |
| Samuelssonia | Gunnar Samuelsson (1885–1944), Swedish botanist from the Uppsala University | Acanthaceae | Bt |
| Sanchezia | José Sánchez (d. c. 1794), Spanish professor of botany | Acanthaceae | St |
| Sandbergia | John Herman Sandberg (1848–1917), Swedish-born American doctor, botanist and agronomist | Brassicaceae | Bu |
| Sandemania | Christopher Albert Walter Sandeman (1882–1951), English botanist and traveler; collected in South America | Melastomataceae | Bu |
| Sanderella | Henry Frederick Conrad Sander (1847–1920) | Orchidaceae | Bu |
| Sandersonia | John Sanderson (1820–1881), Scottish horticulturist | Colchicaceae | Ba |
| Sandwithia | Noel Yvri Sandwith (1901–1965), English botanist at Kew Gardens | Euphorbiaceae | Qu |
| Sanjappa | Munivenkatappa Sanjappa (b. 1951), Indian botanist | Fabaceae | Bt |
| Sankowskya | Garry Sankowsky (fl. 1960–2003), Australian photographer and plant collector | Picrodendraceae | Bu |
| Sannantha | Sanna Wilson, wife of the Australian botanist Peter Gordon Wilson (b. 1950), the author of the genus | Myrtaceae | Bu |
| Santiria | Bapa Santir, Sundanese man from Java who led a botanical exploration of Mount Salak | Burseraceae | Qu |
| Santisukia | Thawatchai Santisuk (b. 1944), Thai herbarium director in Bangkok | Bignoniaceae | Bu |
| Santosia | Talmón Soares dos Santos (1935–2012), Brazilian biologist and collector in Itabuna | Asteraceae | Bu |
| Sanvitalia | Conte Stefano Sanvitale (1764–1838) and/or Federico Sanvitale (1770–1819) | Asteraceae | St |
| Saposhnikovia | Vasili Vasilievich Saposhnikow (1861–1924), Russian geographer and professor of botany in Tomsk | Apiaceae | Bu |
| Sapphoa | Sappho (c. 630 BC – c. 570 BC), poet | Acanthaceae | Bu |
| Saracha | Isidoro Saracha (1733–1803), Spanish monk, apothecary and botanist at the Abbey of Santo Domingo de Silos | Solanaceae | Bu |
| Sargentodoxa | Charles Sprague Sargent (1841–1927) | Lardizabalaceae | St |
| Sarmienta | Martín Sarmiento (1695–1772) | Gesneriaceae | Ba |
| Sarracenia | Michel Sarrazin (1659–1736) | Sarraceniaceae | Ch |
| Sartwellia | Henry Parker Sartwell (1792–1867) | Asteraceae | Bu |
| Satakentia | Toshihiko Satake (1910–1998), Japanese factory owner, producer of rice-processing equipment; also an expert in Arecaceae | Arecaceae | Bu |
| Saundersia | William Wilson Saunders (1809–1879) | Orchidaceae | Bu |
| Saurauia | Franz Josef Graf von Saurau (1760–1832), Austrian nobleman and politician; ambassador in Madrid and Florence | Actinidia | Bu |
| Saussurea | Horace Bénédict de Saussure (1740–1799) and his son Nicolas Théodore de Saussure (1767–1845) | Asteraceae | St |
| Sauvagesia | François Boissier de Sauvages de Lacroix (1706–1767) | Ochnaceae | Bu |
| Sauvallea | Francisco Adolfo Sauvalle (1807–1879), Cuban botanist and expert in molluscs | Commelinaceae | Bu |
| Savia | Gaetano Savi (1769–1844) | Phyllanthaceae | Bu |
| Savignya | Marie Jules César Savigny (1777–1851) | Brassicaceae | Bu |
| Saxegothaea | Albert, Prince Consort (1819–1861) | Podocarpaceae | Co |
| Saxofridericia | Frederick Augustus II of Saxony (1797–1854) | Rapateaceae | Bu |
| Scabrethia | Nathaniel Jarvis Wyeth (1802–1856), businessman and explorer | Asteraceae | Bu |
| Scagea | Herbert Kenneth Airy Shaw (1902–1985) | Picrodendraceae | Bu |
| Scalesia | William Alexander Stables (1810–1890) | Asteraceae | Bu |
| Scaligeria | Julius Caesar Scaliger (1484–1558) | Apiaceae | Bu |
| Schaefferia | Jacob Christian Schäffer (1718–1790) | Celastraceae | Bu |
| Schaueria | Johannes Conrad Schauer (1813–1848) and his brother Sebastian Schauer (1814–1850), German botanist at botanical gardens in present-day Wrocław and Berlin | Acanthaceae | St |
| Schefferomitra | Rudolph Scheffer (1844–1880) | Annonaceae | Qu |
| Schefflera | Johann Peter Ernst von Scheffler (b. 1739), Polish physician | Araliaceae | Co |
| Schefflerodendron | Georg Richard Otto Scheffler (c. 1875 – 1911), German gardener and botanist at the botanical garden in Dahlem, Berlin | Fabaceae | Bu |
| Schelhammera | Günther Christoph Schelhammer (1649–1716), German doctor and professor of botany at the universities in Helmstedt, Jena and Kiel | Colchicaceae | Bu |
| Schenckochloa | Heinrich Schenck (1860–1927) | Poaceae | Bu |
| Schenkia | August Schenk (1815–1891) | Gentianaceae | Bu |
| Scherya | Robert Walter Schery (1917–1987), American botanist at the Missouri Botanical Garden | Asteraceae | Bu |
| Scheuchzeria | Johann Gaspar Scheuchzer (1684–1738) and his brother Johann Jacob Scheuchzer (1672–1733) | Scheuchzeriaceae | Bu |
| Schickendantziella | Friedrich Schickendantz (1837–1896) | Amaryllidaceae | Bu |
| Schiedea | Christian Julius Wilhelm Schiede (1798–1836) | Caryophyllaceae | Bu |
| Schiedeella | Christian Julius Wilhelm Schiede (1798–1836) | Orchidaceae | Bu |
| Schiekia | Friedrich Wilhelm Schieck (1790–1870), German optician and artist | Haemodoraceae | Bu |
| Schimpera | Georg Wilhelm Schimper (1804–1878) | Brassicaceae | Qu |
| Schindleria | Anton Karl Schindler (1879–1964) | Petiveriaceae | Bu |
| Schinziella | Hans Schinz (1858–1941) | Gentianaceae | Qu |
| Schinziophyton | Hans Schinz (1858–1941) | Euphorbiaceae | Qu |
| Schippia | William A. Schipp (1891–1967) | Arecaceae | Qu |
| Schischkinia | Boris Schischkin (1886–1963) | Asteraceae | Bu |
| Schivereckia | Swibert Burkhart Schivereck (1742–1806), Austrian botanist | Brassicaceae | St |
| Schkuhria | Christian Schkuhr (1741–1811) | Asteraceae | Bu |
| Schlagintweitia | Adolf Schlagintweit (1829–1857) and his brothers Hermann (1826–1882) and Robert (1833–1885) | Asteraceae | Bu |
| Schlechtendalia | Diederich Friedrich Karl von Schlechtendal (1767–1842), German lawyer and botanist in Berlin, Minden und Paderborn; father of the botanist Diederich Franz Leonhard von Schlechtendal | Asteraceae | Bu |
| Schlechteranthus | Max Schlechter (1874–1960), brother and colleague of Rudolf Schlechter | Aizoaceae | Bu |
| Schlechterella | Rudolf Schlechter (1872–1925) | Apocynaceae | Qu |
| Schlechterina | Rudolf Schlechter (1872–1925) | Passifloraceae | Qu |
| Schlegelia | Hermann Schlegel (1804–1884) | Schlegeliaceae | Bu |
| Schleichera | Johann Christoph Schleicher (1768–1834), German-Swiss apothecary and botanist in Bex | Sapindaceae | Bu |
| Schleinitzia | Georg von Schleinitz (1834–1910), German vice-admiral and colonial administrator | Fabaceae | Bu |
| Schlimia | Louis Joseph Schlim (1819–1863), Belgian plant collector in South and Central America | Orchidaceae | Bu |
| Schlumbergera | Frédéric Emile Schlumberger (1823–1893), cactus collector | Cactaceae | Co |
| Schmardaea | Ludwig Karl Schmarda (1819–1908) | Meliaceae | Bu |
| Schmidtia | Franz Wilibald Schmidt (1764–1796), Bohemian doctor, zoologist and professor of botany; also a botanical painter | Poaceae | Bu |
| Schmidtottia | Friedrich Schmidt-Ott (1860–1956), lawyer, politician, Prussian official | Rubiaceae | Bu |
| Schnabelia | Rudolf Schnabel (20th century), merchant in Changsha, China, who assisted Heinrich von Handel-Mazzetti | Lamiaceae | Bu |
| Schnella | Jakob Rudolf Schnell (1778–1856), Swiss industrialist, banker and philanthropist | Fabaceae | Bu |
| Schoenefeldia | Wladimir de Schoenefeld (1816–1875) | Poaceae | Bu |
| Schoenia | Johann or Johannes Matthias Albrecht Schoen (1800–1870), German eye doctor, botanist and illustrator | Asteraceae | Bu |
| Schoepfia | Johann David Schoepff (1752–1800) | Schoepfiaceae | Bu |
| Scholtzia | Johann Eduard Heinrich Scholtz (1812–1859), German doctor, botanist and entomologist in present-day Wrocław | Myrtaceae | Bu |
| Schomburgkia | Robert Hermann Schomburgk (1804–1865) | Orchidaceae | St |
| Schotia | Richard van der Schot (d. 1819), gardener at Schönbrunn Palace in Vienna | Fabaceae | St |
| Schottariella | Heinrich Wilhelm Schott (1794–1865) | Araceae | Bu |
| Schottarum | Heinrich Wilhelm Schott (1794–1865) | Araceae | Bu |
| Schoutenia | Willem Schouten (c. 1580 – 1625), navigator | Malvaceae | Bu |
| Schouwia | Joakim Frederik Schouw (1789–1852) | Brassicaceae | Bu |
| Schradera | Heinrich Schrader (1767–1836) | Rubiaceae | Bu |
| Schrebera | Johann Christian Daniel von Schreber (1739–1810) | Oleaceae | Bu |
| Schreiteria | Carlos Rodolfo Schreiter (1877–1942), German-Argentinian botanist, student of Miguel Lillo | Montiaceae | Bu |
| Schrenkia | Alexander von Schrenk (1816–1876) | Apiaceae | Bu |
| Schtschurowskia | Gregory Ephimovich Shchurovsky (1803–1884) | Apiaceae | Bu |
| Schubertia | Gotthilf Heinrich von Schubert (1780–1860) | Apocynaceae | St |
| Schuitemania | André Schuiteman (b. 1960) | Orchidaceae | Bu |
| Schultesia | Josef August Schultes (1773–1831) | Gentianaceae | Bu |
| Schultesianthus | Richard Evans Schultes (1915–2001) | Solanaceae | Bu |
| Schultesiophytum | Richard Evans Schultes (1915–2001) | Cyclanthaceae | Bu |
| Schulzia | Karl Friedrich Schultz (1766–1837), German doctor and botanist, and Johann Heinrich Schulze (1687–1744) | Apiaceae | Bu |
| Schumacheria | Heinrich Christian Friedrich Schumacher (1757–1830) | Dilleniaceae | Bu |
| Schumannianthus | Karl Moritz Schumann (1851–1904) | Marantaceae | Bu |
| Schumanniophyton | Karl Moritz Schumann (1851–1904) | Rubiaceae | Bu |
| Schunkea | Vital Schunk (fl. 1990–1999), co-collector of this plant in southeast Brazil | Orchidaceae | Bu |
| Schuurmansia | Jacobus Hermanus Schuurmans Stekhoven (1792–1855), Dutch botanical garden curator in Leiden | Ochnaceae | Qu |
| Schuurmansiella | Jacobus Hermanus Schuurmans Stekhoven (1792–1855), Dutch botanical garden curator in Leiden | Ochnaceae | Qu |
| Schwackaea | Carl August Wilhelm Schwacke (1848–1904) | Melastomataceae | Bu |
| Schwalbea | Georg Christian Schwalbe (1691–1761), Dutch doctor and botanist | Orobanchaceae | Bu |
| Schwantesia | Martin Heinrich Gustav Schwantes (1891–1960) | Aizoaceae | Bu |
| Schwartzia | Olof Swartz (1760–1818) | Marcgraviaceae | Bu |
| Schweiggeria | August Friedrich Schweigger (1783–1821) | Violaceae | Bu |
| Schweinfurthia | Georg August Schweinfurth (1836–1925) | Plantaginaceae | Bu |
| Schwenckia | Martinus Wilhelmus Schwencke (1707–1785), Dutch doctor and botanist in The Hague with a medicine garden | Solanaceae | Bu |
| Schwendenera | Simon Schwendener (1829–1919) | Rubiaceae | Bu |
| Scopolia | Giovanni Antonio Scopoli (1723–1788) | Solanaceae | Co |
| Scottellia | George Francis Scott Elliot (1862–1934) | Achariaceae | Bu |
| Searsia | Paul Sears (1891–1990) | Anacardiaceae | Bu |
| Sebaea | Albertus Seba (1665–1736) | Gentianaceae | Bu |
| Sebastiania | Francesco Antonio Sebastiani (1782–1821), Italian doctor, professor of botany and university botanical garden director in Rome | Euphorbiaceae | Bu |
| Sebastiano-schaueria | Sebastian Schauer (1814–1850), German gardener and botanist at botanical gardens in present-day Wrocław and Berlin | Acanthaceae | Bu |
| Secondatia | Jean-Baptiste de Secondat (1716–1796) | Apocynaceae | Bu |
| Seegeriella | Hans Gerhard Seeger (b. 1939), German gardener at botanical gardens in Göttingen, Hanover and Heidelberg | Orchidaceae | Bu |
| Seemannaralia | Berthold Carl Seemann (1825–1871) | Araliaceae | Bu |
| Seemannia | Berthold Carl Seemann (1825–1871) | Gesneriaceae | Bu |
| Seetzenia | Ulrich Jasper Seetzen (1767–1811) | Zygophyllaceae | Bu |
| Seguieria | Jean-François Séguier (1703–1784) | Petiveriaceae | Bu |
| Seidelia | perhaps Carl Friedrich Seidel (d. 1898), German painter and botanist, and/or Jacob Friedrich Seidel (1789–1860), German gardener, and/or Johann Heinrich Seidel (1744–1815), German court gardener, and/or Traugott Leberecht Seidel (1775–1815), German gardener | Euphorbiaceae | Bu |
| Seidenfadenia | Gunnar Seidenfaden (1908–2001) | Orchidaceae | Bu |
| Seidlitzia | Nikolai Karl Samuel von Seidlitz (1831–1907), Baltic German botanist and statistician | Amaranthaceae | Bu |
| Selkirkia | Alexander Selkirk (1676–1721), sailor and castaway | Boraginaceae | Bu |
| Selliera | François Noël Sellier (1737–1809), French botanical illustrator | Goodeniaceae | St |
| Selloa | Friedrich Sellow (1789–1831) | Asteraceae | Qu |
| Sellocharis | Friedrich Sellow (1789–1831) | Fabaceae | Qu |
| Selysia | Edmond de Sélys Longchamps (1813–1900) | Cucurbitaceae | Bu |
| Semenovia | Pyotr Semyonov-Tyan-Shansky (1827–1914) | Apiaceae | Bu |
| Semiria | João Semir (b. 1937), Brazilian botanist, specialist in Asteraceae | Asteraceae | Bu |
| Senaea | Joaquim Candido da Costa Sena (1852–1919), Brazilian geologist and plant collector | Gentianaceae | Bu |
| Senefeldera | Alois Senefelder (1771–1834), lithographer | Euphorbiaceae | Bu |
| Senefelderopsis | Alois Senefelder (1771–1834), lithographer | Euphorbiaceae | Bu |
| Senra | Buenaventura Serra y Ferragut (1728–1784), Spanish lawyer and professor at the university in Mallorca; a member of the royal academy of history and a cofounder of the Mallorcan branch of the Sociedad Económica de los Amigos del País | Malvaceae | Bu |
| Sequoia | Sequoyah (c. 1770 – 1843), Cherokee linguist | Cupressaceae | Co |
| Sequoiadendron | Sequoyah (c. 1770 – 1843), Cherokee linguist | Cupressaceae | Co |
| Serenoa | Sereno Watson (1826–1892) | Arecaceae | St |
| Sergia | Serguéi Vassílievich Juzepczuk or Sergueï Vassilievitch Yuzepchúk (1893–1959), Russian botanist at the university botanical garden in Saint Petersburg, specialist in Solanaceae | Campanulaceae | Bu |
| Seringia | Nicolas Charles Seringe (1776–1858) | Malvaceae | Bu |
| Serjania | Philippe Sergeant (17th century), French monk and botanist | Sapindaceae | St |
| Serruria | Joseph Serrurier (1663–1742), Dutch doctor and natural scientist; professor first in philosophy and mathematics, then in medicine and botany at the university in Utrecht | Proteaceae | Bu |
| Sersalisia | Gerolamo Sersale (1584–1654), astronomer | Sapotaceae | Bu |
| Sesleria | Leonard Sesler (d. 1785), German-Italian doctor and botanist who maintained a large botanical garden | Poaceae | Co |
| Sesleriella | Leonard Sesler (d. 1785), German-Italian doctor and botanist who maintained a large botanical garden | Poaceae | Bu |
| Sessea | Martín Sessé y Lacasta (1751–1808) | Solanaceae | Bu |
| Setchellanthus | William Albert Setchell (1864–1943) | Setchellanthaceae | Bu |
| Severinia | Marco Aurelio Severino (1580–1656), anatomist | Rutaceae | St |
| Sextonia | André Joseph Guillaume Henri Kostermans (1906–1994) | Lauraceae | Bu |
| Seymeria | Henry Seymer (1745–1800), English amateur botanist | Orobanchaceae | Bu |
| Seymeriopsis | Henry Seymer (1745–1800), English amateur botanist | Orobanchaceae | Bu |
| Seyrigia | André Seyrig (1897–1945), French amateur entomologist and botanist from Alsace; mining director in the Bekily District of Madagascar | Cucurbitaceae | Bu |
| Shafera | John Adolph Shafer (1863–1918) | Asteraceae | Bu |
| Shaferocharis | John Adolph Shafer (1863–1918) | Rubiaceae | Bu |
| Shangwua | Shang Wu Liu (b. 1934), Chinese botanist, taxonomist and professor in the province of Qinghai, China | Asteraceae | Bu |
| Sheareria | George Campbell Shearer (1836–1892), Scottish doctor; taught botany at the school of medicine in Liverpool | Asteraceae | Bu |
| Sheilanthera | Sheila Williams, wife and colleague of Ion James Muirhead Williams (1912–2001), South African botanist and author of the genus | Rutaceae | Bu |
| Shepherdia | John Shepherd (1765–1836), English botanist | Elaeagnaceae | Co |
| Sherardia | William Sherard (c. 1658 – 1728) | Rubiaceae | Bu |
| Sherbournia | Margaret Dorothea Sherbourne, born Willis (1791–1846), English plant collector | Rubiaceae | Bu |
| Shibataea | Keita Shibata (1878–1949) | Poaceae | Co |
| Shinnersia | Lloyd Herbert Shinners (1918–1971) | Asteraceae | Qu |
| Shinnersoseris | Lloyd Herbert Shinners (1918–1971) | Asteraceae | Qu |
| Shiuyinghua | Shiu-Ying Hu (1910–2012) | Paulowniaceae | Bu |
| Shonia | Enid Lynette Henderson (d. 1991), wife of Rodney John Francis Henderson, the author of the genus | Euphorbiaceae | Bu |
| Shorea | John Shore, 1st Baron Teignmouth (1751–1834) | Dipterocarpaceae | Bu |
| Shortia | Charles Wilkins Short (1794–1863) | Diapensiaceae | St |
| Shuteria | James Shuter (1795–1826), English doctor and botanist; collected plants in present-day Chennai, India | Fabaceae | Bu |
| Sibbaldia | Robert Sibbald (1641–1722) | Rosaceae | St |
| Sibbaldianthe | Robert Sibbald (1641–1722) | Rosaceae | Bu |
| Sibthorpia | Humphry Sibthorp (1713–1797) | Plantaginaceae | St |
| Sidneya | Sidney Fay Blake (1892–1959) | Asteraceae | Bu |
| Siebera | Franz Sieber (1789–1844) | Asteraceae | Bu |
| Siemensia | Werner von Siemens (1816–1892), inventor and industrialist | Rubiaceae | Bu |
| Sievekingia | Friedrich Sieveking (1798–1872), German lawyer and politician in Hamburg | Orchidaceae | Bu |
| Sieversandreas | Andreas Sievers (1931–2009), German botanist, director of the university botanical garden in Bonn, professor of cell biology | Orobanchaceae | Bu |
| Sieversia | Johann August Carl Sievers (1762–1795) | Rosaceae | Bu |
| Sigesbeckia | Johann Georg Siegesbeck (1686–1755), botanist and critic of Carl Linnaeus | Asteraceae | St |
| Silvianthus | Francis De Silva, collector for Nathaniel Wallich | Carlemanniaceae | Bu |
| Silviella | Baltasar da Silva Lisboa (1761–1840), Brazilian lawyer and natural historian | Orobanchaceae | Bu |
| Simmondsia | Thomas William Simmonds (1767–1804), English doctor and naturalist | Simmondsiaceae | Ba |
| Simsia | John Sims (1749–1831) | Asteraceae | Bu |
| Sinclairia | Andrew Sinclair (1794–1861) | Asteraceae | Bu |
| Sinningia | Wilhelm Werner Carl Sinning (1791–1874), German horticulturist | Gesneriaceae | Co |
| Sinochasea | Mary Agnes Chase (1869–1963) | Poaceae | Bu |
| Sinodielsia | Ludwig Diels (1874–1945) | Apiaceae | Bu |
| Sinofranchetia | Adrien René Franchet (1834–1900) | Lardizabalaceae | Bu |
| Sinojackia | John George Jack (1861–1949) | Styracaceae | Ba |
| Sinojohnstonia | Ivan Murray Johnston (1898–1960) | Boraginaceae | Bu |
| Sinolimprichtia | Hans Wolfgang Limpricht (b. 1877), German botanist; collected plants in China and Japan | Apiaceae | Bu |
| Sinowilsonia | Ernest Henry Wilson (1876–1930) | Hamamelidaceae | St |
| Siraitia | Harley Harris Bartlett (1886–1960) | Cucurbitaceae | Bu |
| Sirdavidia | David Frederick Attenborough (b. 1926) | Annonaceae | Bt |
| Sirhookera | Joseph Dalton Hooker (1817–1911) | Orchidaceae | Bu |
| Sirindhornia | Sirindhorn (b. 1955), princess | Orchidaceae | Bu |
| Sladenia | Edward Bosc Sladen (1827–1890), army officer | Sladeniaceae | Bu |
| Sleumerodendron | Hermann Otto Sleumer (1906–1993) | Proteaceae | Bu |
| Sloanea | Hans Sloane (1660–1753) | Elaeocarpaceae | Bu |
| Smallanthus | John Kunkel Small (1869–1938) | Asteraceae | Bu |
| Smelowskia | Timotheus Smelowsky (1769–1815), Russian apothecary and botanist, professor of chemistry and medicine in Saint Petersburg | Brassicaceae | Bu |
| Smirnowia | Sergej Smirnoff, student who accompanied Alexander von Middendorff to Kokand in present-day Uzbekistan and collected plants on the southeast coast of the Aral Sea | Fabaceae | Bu |
| Smithia | James Edward Smith (1759–1828) | Fabaceae | Bu |
| Smithiantha | Matilda Smith (1854–1926) | Gesneriaceae | St |
| Smithsonia | James Smithson (c. 1765 – 1829) | Orchidaceae | Bu |
| Smitinandia | Tem Smitinand (1920–1995), director of the Royal Thailand Department of Forestry; orchid taxonomist | Orchidaceae | Bu |
| Smythea | William James Smythe (1816–1887), military officer | Rhamnaceae | Bu |
| Snowdenia | Joseph Devenport Snowden (1886–1973), British gardener, botanist and mycologist; worked at Kew Gardens | Poaceae | Qu |
| Soaresia | Sebastião or Sebastián Ferreira Soares (1820–1887), Brazilian administrator; wrote about agricultural finances and statistics | Asteraceae | Bu |
| Sobennikoffia | Alexandra Vasilewna Schlechter, born Sobennikoff, wife of the author of the genus, Rudolf Schlechter | Orchidaceae | Bu |
| Sobolewskia | Gregor Federovitch Sobolewsky or Gregoriy Federowich Sobolewski (1741–1807), Russian military doctor, botanist and mycologist; botanical garden director in Saint Petersburg and professor of botany | Brassicaceae | Bu |
| Sobralia | Francisco Martinez Sobral (d. 1799), Spanish physician | Orchidaceae | St |
| Socratea | Socrates (469–399 BC), philosopher | Arecaceae | Bu |
| Soehrensia | Johannes Soehrens (d.1934) Dutch botanist and Professor and Director of the Botanical Garden in Santiago de Chile | Cactaceae | Bt |
| Soejatmia | Soejatmi Dransfield (b. 1939) | Poaceae | Bu |
| Soemmeringia | Samuel Thomas von Sömmerring (1755–1830), anatomist | Fabaceae | Bu |
| Sohmaea | Kankichi Sohma (1755–1830), Japanese botanist who worked at Tohoku University, Japan | Fabaceae | Bt |
| Sohnreyia | Heinrich Sohnrey (1859–1948), German teacher and writer | Rutaceae | Bu |
| Sohnsia | Ernest Reeves Sohns (1917–2001), American botanist at the National Museum of Natural History | Poaceae | Bu |
| Solandra | Daniel Solander (1733–1782) | Solanaceae | St |
| Soleirolia | Henri-Augustin Soleirol, French military engineer and botanist in Corsica (1792–1860) | Urticaceae | Co |
| Soliva | Salvador Soliva (c. 1750 – 1793), Spanish botanist and doctor at the Spanish court in Madrid; professor of botany | Asteraceae | Bu |
| Solms-laubachia | Hermann zu Solms-Laubach (1842–1915) | Brassicaceae | Qu |
| Solmsia | Hermann zu Solms-Laubach (1842–1915) | Thymelaeaceae | Qu |
| Solonia | Solon (c. 640 BC – c. 560 BC), statesman | Primulaceae | Bu |
| Sommera | Christian Niefeldt Sommer (1821–1878), entomologist; supported the research of author of the genus, Diederich Friedrich Carl von Schlechtendal | Rubiaceae | Bu |
| Sommerfeltia | Søren Christian Sommerfelt (1794–1838) | Asteraceae | Qu |
| Sommieria | Carlo Pietro Stefano Sommier (1848–1922), French-born Italian botanist and natural historian who collected across Europe and in the Caucasus | Arecaceae | Bu |
| Somrania | Somran Suddee (fl. 1998); worked at the Forest Herbarium in Bangkok in Thailand | Gesneriaceae | Bu |
| Sondottia | Otto Wilhelm Sonder (1812–1881) | Asteraceae | Bu |
| Sonneratia | Pierre Sonnerat (1749–1814) | Lythraceae | Bu |
| Sotoa | Miguel Ángel Soto Arenas (1963–2009), Mexican botanist, specialist in Mexican and Central American orchids | Orchidaceae | Bu |
| Souroubea | James Sowerby (1757–1822) | Marcgraviaceae | Bu |
| Sowerbaea | James Sowerby (1757–1822) | Asparagaceae | Bt |
| Soyauxia | Hermann Soyaux (1852–1928), German gardener, botanist and African explorer | Peridiscaceae | Bu |
| Spachea | Édouard Spach (1801–1879) | Malpighiaceae | Bu |
| Sparrmannia | Anders Sparrman (1748–1820) | Malvaceae | St |
| Specklinia | Veit Rudolf Specklin (d. 1550), engraver in Strasbourg (now a French city) | Orchidaceae | Bu |
| Spegazziniophytum | Carlo Luigi Spegazzini (1858–1926) | Euphorbiaceae | Bu |
| Spenceria | Spencer Le Marchant Moore (1850–1931) | Rosaceae | St |
| Speranskia | Mikhail Speransky (1772–1839), statesman | Euphorbiaceae | Bu |
| Spetaea | Franz Speta (1941–2015) | Asparagaceae | Bu |
| Spigelia | Adriaan van den Spiegel (1578–1625), anatomist | Loganiaceae | Co |
| Spragueanella | Thomas Archibald Sprague (1877–1958) | Loranthaceae | Bu |
| Sprekelia | Johann Heinrich von Sprekelsen (1691–1764), botanist in Hamburg | Amaryllidaceae | St |
| Sprengelia | Christian Konrad Sprengel (1750–1816) | Ericaceae | Bu |
| Staavia | Martin Staaf (1731–1788), correspondent with Carl Linnaeus, in Gothenburg | Bruniaceae | Bu |
| Staberoha | Johann Heinrich Ludwig Staberoh (1785–1857), German apothecary and teacher at a veterinary school; member of the examination board for apothecaries | Restionaceae | Bu |
| Stackhousia | John Stackhouse (1742–1819) | Celastraceae | Bu |
| Stadtmannia | Jean Frédéric Stadtmann (1762–1807), French doctor, botanist and draftsman | Sapindaceae | Bu |
| Staehelina | Benedikt Stähelin (1695–1750), Swiss doctor and natural scientist; professor of physics at the University of Basel | Asteraceae | Bu |
| Staelia | Auguste Louis de Staël-Holstein (1790–1827), French philanthropist | Rubiaceae | Bu |
| Stalkya | Galfrid Clement Keyworth Dunsterville (1905–1988), English engineer; specialist in orchids | Orchidaceae | Bu |
| Standleya | Paul Carpenter Standley (1884–1963) | Rubiaceae | Bu |
| Standleyanthus | Paul Carpenter Standley (1884–1963) | Asteraceae | Bu |
| Stanfieldiella | Dennis Percival Stanfield (1903–1971), British botanist and taxonomist in the Nigerian Civil Service | Commelinaceae | Bu |
| Stangeria | William Stanger (1811–1854) | Zamiaceae | St |
| Stanhopea | Philip Henry Stanhope, 4th Earl Stanhope (1781–1855) | Orchidaceae | St |
| Stanleya | Edward Smith-Stanley, 13th Earl of Derby (1775–1851) | Brassicaceae | Bu |
| Stanmarkia | Paul Carpenter Standley (1884–1963) and Julian Alfred Steyermark (1909–1988) | Melastomataceae | Bu |
| Stapelia | Johannes Bodaeus van Stapel (c. 1600 – 1636) | Apocynaceae | St |
| Stapelianthus | Johannes Bodaeus van Stapel (c. 1600 – 1636) | Apocynaceae | Qu |
| Stapeliopsis | Johannes Bodaeus van Stapel (c. 1600 – 1636) | Apocynaceae | Qu |
| Stapfiella | Otto Stapf (1857–1933) | Passifloraceae | Bu |
| Stapfochloa | Otto Stapf (1857–1933) | Poaceae | Bu |
| Staudtia | Alois Staudt (d. 1897), German botanist; collected plants in Kamerun (now Cameroon) | Myristicaceae | Bu |
| Staufferia | Hans Ulrich Stauffer (1929–1965), Swiss botanist who traveled in South Africa, Australia and New Guinea; specialist in Santalaceae | Santalaceae | Bu |
| Stauntonia | George Staunton, 1st Baronet (1737–1801), botanist | Lardizabalaceae | Co |
| Stawellia | William Stawell (1815–1889), politician and judge | Asphodelaceae | Bu |
| Stayneria | Frank J. Stayner (1907–1981), South African horticulturist, specialist in succulents; curator at the Karoo botanical garden | Aizoaceae | Bu |
| Steenisia | Cornelis Gijsbert Gerrit Jan van Steenis (1901–1986) | Rubiaceae | Bu |
| Stefanoffia | Boris Stefanoff (1894–1979), Bulgarian botanist, curator at the herbarium of Sofia University | Apiaceae | Bu |
| Steinbachiella | José Steinbach (1856–1929), collector in Bolivia and Argentina | Fabaceae | Bu |
| Stellera | Georg Wilhelm Steller (1709–1746) | Thymelaeaceae | St |
| Stephanbeckia | Stephan Georg Beck (b. 1944), botanist from Missouri Botanical Garden | Asteraceae | Bt |
| Sternbergia | Kaspar Maria von Sternberg (1761–1838) | Amaryllidaceae | Co |
| Stetsonia | Francis Lynde Stetson (1846–1920), lawyer | Cactaceae | St |
| Steudnera | Hermann Steudner (1832–1863) | Araceae | Bu |
| Stevenia | Christian von Steven (1781–1863) | Brassicaceae | Bu |
| Steveniella | Christian von Steven (1781–1863) | Orchidaceae | Bu |
| Stevensia | Edward Stevens (1755–1834), doctor and diplomat | Rubiaceae | Bu |
| Stevia | Pedro Jaime Esteve (c. 1500 – 1556) | Asteraceae | St |
| Steviopsis | Pedro Jaime Esteve (c. 1500 – 1556) | Asteraceae | Bu |
| Stewartia | John Stuart, 3rd Earl of Bute (1713–1792), prime minister of Great Britain | Theaceae | Co |
| Stewartiella | Ralph Randles Stewart (1890–1993) | Apiaceae | Bu |
| Steyerbromelia | Julian Alfred Steyermark (1909–1988) | Bromeliaceae | Bu |
| Steyermarkia | Julian Alfred Steyermark (1909–1988) | Rubiaceae | Bu |
| Steyermarkina | Julian Alfred Steyermark (1909–1988) | Asteraceae | Bu |
| Steyermarkochloa | Julian Alfred Steyermark (1909–1988) | Poaceae | Bu |
| Stifftia | Andreas Joseph Freiherr von Stifft (1760–1836), Austrian doctor in Vienna; also an imperial personal physician | Asteraceae | Bu |
| Stillingia | Benjamin Stillingfleet (1702–1771) | Euphorbiaceae | Bu |
| Stimpsonia | William Stimpson (1832–1872) | Primulaceae | Bu |
| Stirlingia | James Stirling (1791–1865), colonial administrator | Proteaceae | Qu |
| Stirtonanthus | Charles Howard Stirton (b. 1946), South African botanist and taxonomist; later a director at Kew Gardens | Fabaceae | Bu |
| Stocksia | John Ellerton Stocks (1822–1854) | Sapindaceae | Bu |
| Stockwellia | Victor Charles Stockwell (1918–1999), Australian forest ranger in Queensland | Myrtaceae | Bu |
| Stoeberia | Ernst Stoeber (1889–1927?), German teacher and botanist in Lüderitz in present-day Namibia | Aizoaceae | Bu |
| Stokesia | Jonathan Stokes (1755–1831) | Asteraceae | Co |
| Stonesia | Margaret Stones (b. 1920) | Podostemaceae | Bu |
| Stonesiella | Margaret Stones (b. 1920) | Fabaceae | Bu |
| Storckiella | Jacob Storck (1836–1893), German-born Australian gardener from Darmstadt; accompanied the author of the genus, Berthold Carl Seemann, on a plant-collecting expedition | Fabaceae | Bu |
| Strangea | Frederick Strange (1826–1854), English-born Australian seaman who operated an export business in Sydney for plant and animal specimens, most collected by him | Proteaceae | Bu |
| Stranvaesia | William Fox-Strangways, 4th Earl of Ilchester (1795–1865) | Rosaceae | St |
| Strasburgeria | Eduard Strasburger (1844–1912) | Strasburgeriaceae | Bu |
| Strelitzia | Charlotte of Mecklenburg-Strelitz (1744–1818) | Strelitziaceae | Ch |
| Strempeliopsis | Johannes Carl Friedrich Strempel (1800–1872), German eye doctor and natural scientist; later a professor in Rostock | Apocynaceae | Bu |
| Strotheria | John Lance Strother (b. 1941), American botanist at the university herbarium in Berkeley, California | Asteraceae | Bu |
| Strumpfia | Christoph Carl Strumpff (d. 1754), German doctor, professor of chemistry in Halle | Rubiaceae | Bu |
| Stuartina | Charles Stuart (1802–1877), English botanist, gardener and traveler; collected in Australia and New Zealand | Asteraceae | Qu |
| Stuckenia | Wilhelm Adolf Stucken (1860–1901), German teacher of Latin, Greek and German at a school in Bremen; built up a herbarium and botanical garden | Potamogetonaceae | Bu |
| Stuhlmannia | Franz Stuhlmann (1863–1928) | Fabaceae | Qu |
| Stutzia | Howard Stutz (1918–2010) | Amaranthaceae | Bu |
| Suarezia | Carola Lindberg de Súarez, South American orchid collector and illustrator | Orchidaceae | Bu |
| Succowia | Georg Adolf Suckow (1751–1813) | Brassicaceae | Bu |
| Suchtelenia | Paul van Suchtelen (1788–1833), Dutch-born Russian military officer | Boraginaceae | Bu |
| Suckleya | George Suckley (1830–1869) | Amaranthaceae | Bu |
| Suessenguthia | Karl Suessenguth (1893–1955) | Acanthaceae | Bu |
| Suessenguthiella | Karl Suessenguth (1893–1955) | Molluginaceae | Bu |
| Suksdorfia | Wilhelm Nikolaus Suksdorf (1850–1932) | Saxifragaceae | Bu |
| Sullivantia | William Starling Sullivant (1803–1873) | Saxifragaceae | Bu |
| Summerhayesia | V. S. Summerhayes (1897–1974) | Orchidaceae | Bu |
| Sunhangia | Hang Sun (b.1963), Chinese botanist, Professor of Botany and Director of the Kunming Institute of Botany in Yunnan | Fabaceae | Bt |
| Suriana | Joseph Donat Surian (1650–1691), French doctor, chemist and botanist | Surianaceae | Bu |
| Surreya | Surrey Wilfrid Laurance Jacobs (1946–2009), Australian botanist and botanical garden taxonomist in Sydney | Amaranthaceae | Bu |
| Sutera | Johann Rudolf Suter (1766–1827) | Scrophulariaceae | Bu |
| Sutherlandia | James Sutherland (1639–1719) | Fabaceae | St |
| Suzukia | Shigeyoshi Suzuki (1894 – c. 1934), Japanese botanist and plant collector | Lamiaceae | Bu |
| Svenkoeltzia | Sven Koeltz (b. 1941), German book dealer and publisher of scientific books in Königstein in Taunus | Orchidaceae | Bu |
| Swainsona | Isaac Swainson (1746–1812) | Fabaceae | Co |
| Swallenia | Jason Richard Swallen (1903–1991) | Poaceae | Bu |
| Swartzia | Olof Swartz (1760–1818) | Fabaceae | Bu |
| Sweetia | Robert Sweet (1783–1835) | Fabaceae | Bu |
| Swertia | Emanuel Sweert (c. 1552 – 1612) | Gentianaceae | St |
| Swietenia | Gerard van Swieten (1700–1772), doctor | Meliaceae | St |
| Swinglea | Walter Tennyson Swingle (1871–1952) | Rutaceae | Bu |
| Swintonia | George Swinton (1780–1854) | Anacardiaceae | Bu |
| Symonanthus | David Eric Symon (1920–2011), Australian botanist and taxonomist from the University of Adelaide and Waite Agricultural Research Institute | Solanaceae | Bt |
| Symmeria | Robert Symmer (1707–1763), physicist | Polygonaceae | Bu |
| Syreitschikovia | Dmitry Petrovich Syreyshchikov (1868–1932), Russian botanist, curator at the university herbarium in Moscow | Asteraceae | Bu |
| Szovitsia | Johann Nepomuk Szovits (1782–1830), Hungarian-born Russian apothecary and botanist | Apiaceae | Bu |
| Tabernaemontana | Jacobus Theodorus Tabernaemontanus (1522–1590) | Apocynaceae | St |
| Tabernanthe | Jacobus Theodorus Tabernaemontanus (1522–1590) | Apocynaceae | Bu |
| Takhtajania | Armen Takhtajan (1910–2009) | Winteraceae | Qu |
| Takhtajaniantha | Armen Takhtajan (1910–2009) | Asteraceae | Qu |
| Takhtajaniella | Armen Takhtajan (1910–2009) | Brassicaceae | Bu |
| Talbotiella | Dorothy Amaury Talbot (1871–1916) and her husband Percy Amaury Talbot (1877–1945), African anthropologists, explorers and plant collectors | Fabaceae | Bu |
| Tamamschjanella | Sofya Georgiyevna Tamamshyan (1901–1981) | Apiaceae | Bu |
| Tamayorkis | Roberto González Tamayo (1940–2014), Mexican engineer and botanist, professor at the University of Guadalajara | Orchidaceae | Bu |
| Tamijia | Tamiji Inoue (1947–1997), Japanese botanist and zoologist (entomologist) | Zingiberaceae | Bu |
| Tammsia | Georg Tamms, German doctor from Altona (near Hamburg), also a collector | Rubiaceae | Bu |
| Tanakaea | Tanaka Yoshio (1838–1916) | Saxifragaceae | St |
| Tannodia | Alfred Moquin-Tandon (1804–1863) | Euphorbiaceae | Bu |
| Taplinia | Theodore Ernest Holmes Aplin (1927–1991), Burmese-Australian botanist at the Western Australian Herbarium; found this plant | Asteraceae | Bu |
| Tashiroea | Antei Tashiro (1856–1928), Japanese botanist and anthropologist, cofounder of a botanical garden in Taiwan | Melastomataceae | Bu |
| Tasmannia | Abel Tasman (1603–1659), seafarer and explorer | Winteraceae | Qu |
| Tateanthus | George Henry Hamilton Tate (1894–1953) | Melastomataceae | Bu |
| Tateishia | Yoichi Tateishi (b.1948), Japanese botanist and Professor at University of the Ryukyus in Okinawa | Fabaceae | Bt |
| Tatianyx | Tatiana Skvortzov Sendulsky (1922–2004), Russian-born Brazilian botanist who worked at the botanical institute of the University of São Paulo | Poaceae | Bu |
| Tauschia | Ignaz Friedrich Tausch (1793–1848) | Apiaceae | Bu |
| Tavaresia | José Tavares de Macedo (19th century), colonial administrator in Portuguese Angola (present-day Angola) | Apocynaceae | Bu |
| Taverniera | Jean-Baptiste Tavernier (1605–1689), gem merchant and traveler | Fabaceae | Bu |
| Teagueia | Walter Teague (1925–2013), American botanist in San Francisco, collector of orchids | Orchidaceae | Bu |
| Tecophilaea | Tecophila Billotti (1802 or 1803 – 1885 or 1886), Italian botanical artist | Tecophilaeaceae | Ch |
| Teedia | Johann Georg Teede, German botanist who collected plants in Portugal | Scrophulariaceae | Bu |
| Teesdalia | Robert Teesdale (1740–1804), English botanist who worked as head gardener for Frederick Howard, 5th Earl of Carlisle; cofounder of the Linnean Society of London | Brassicaceae | Bu |
| Teijsmanniodendron | Johannes Elias Teijsmann (1808–1882) | Lamiaceae | Bu |
| Teixeiranthus | Alcides Ribeiro Teixeira (1918–2003), Brazilian botanist and mycologist in São Paulo | Asteraceae | Bu |
| Telekia | Sámuel Teleki (1739–1822), nobleman and patron | Asteraceae | Co |
| Telfairia | Charles Telfair (1778–1833) | Cucurbitaceae | Bu |
| Templetonia | John Templeton (1766–1825) | Fabaceae | St |
| Tennantia | James Robert Tennant (b. 1928), British botanist at Kew Gardens | Rubiaceae | Bu |
| Tenrhynea | Willem ten Rhijne (1647–1700) | Asteraceae | Bu |
| Ternstroemia | Christopher Tärnström (1703–1746), student of Linnaeus | Pentaphylacaceae | St |
| Tersonia | Joséphine Louise Moquin-Tandon, born de Terson (1819–1890), wife of the French botanist Alfred Moquin-Tandon, the author of this genus | Gyrostemonaceae | Bu |
| Tessaria | Ludovico Tessari (18th century), Italian doctor and professor of botany in Ancona | Asteraceae | Qu |
| Tessiera | Henri-Alexandre Tessier (1741–1837), French doctor and agronomist | Rubiaceae | Bu |
| Tessmannia | Günther Tessmann (1884–1969), German-Brazilian ethnologist and botanist; African explorer and plant collector; settled in Brazil | Fabaceae | Qu |
| Tessmanniacanthus | Günther Tessmann (1884–1969), German-Brazilian ethnologist and botanist; African explorer and plant collector; settled in Brazil | Acanthaceae | Qu |
| Tessmannianthus | Günther Tessmann (1884–1969), German-Brazilian ethnologist and botanist; African explorer and plant collector; settled in Brazil | Melastomataceae | Qu |
| Testulea | Georges Marie Patrice Charles Le Testu (1877–1967), French colonial administrator in tropical Africa; later worked at a botanical garden in Caen | Ochnaceae | Bu |
| Teuscheria | Henry Teuscher (1891–1984) | Orchidaceae | Bu |
| Teyleria | Pieter Teyler van der Hulst (1702–1778), merchant, collector and patron | Fabaceae | Bu |
| Thalia | Johannes Thal (1542–1583), German botanist | Marantaceae | Co |
| Thamnoldenlandia | Henrik Bernard Oldenland (1663–1697) | Rubiaceae | Bu |
| Thawatchaia | Thawatchai Santisuk (b. 1944), Thai herbarium director in Bangkok, and Thawatchai Wongprasert (fl. 2000), plant collector | Podostemaceae | Bu |
| Theilera | Arnold Theiler (1867–1936), veterinarian | Campanulaceae | Bu |
| Themistoclesia | Themistocles (c. 525 BC – c. 459 BC), politician and military leader | Ericaceae | Bu |
| Thenardia | Louis Jacques Thénard (1777–1857), chemist | Apocynaceae | Bu |
| Theodorovia | Andrey A. Fedorov (1908–1987) | Campanulaceae | Bu |
| Theophrasta | Theophrastus (c. 371 BC – 287 BC) | Primulaceae | St |
| Thepparatia | Sirindhorn (b. 1955), princess | Malvaceae | Bu |
| Thevenotia | Jean de Thévenot (1633–1667) | Asteraceae | Bu |
| Thevetia | André Thevet (1516–1590), clergyman and explorer | Apocynaceae | St |
| Thibaudia | Étienne Thibaud (d. 1813), French doctor and professor of botany, member of a natural history society in Edinburgh and the Linnean Society of London | Ericaceae | Bu |
| Thinouia | André Thouin (1747–1824) | Sapindaceae | Bu |
| Thiollierea | Victor Thiollière (1801–1859) | Rubiaceae | Bu |
| Thiseltonia | George Henry Thiselton-Dyer (1879–1944), English engineer; collected in Australia and New Zealand | Asteraceae | Bu |
| Thismia | Thomas Smith (d. 1825?), English microscopist; worked with Robert Brown | Burmanniaceae | Bu |
| Thomandersia | Thomas Anderson (1832–1870) | Thomandersiaceae | Bu |
| Thomasia | Pierre Thomas (1708–1781) and family, 18th- and 19th-century Swiss collectors | Malvaceae | St |
| Thompsonella | Charles Henry Thompson (1870–1931), American botanist who taught at the Missouri Botanical Garden | Crassulaceae | Bu |
| Thonningia | Peter Thonning (1775–1848) | Balanophoraceae | Bu |
| Thoreauea | Henry David Thoreau (1817–1862), writer and philosopher | Apocynaceae | Bu |
| Thorncroftia | Georg Thorncroft (1857–1934), English-born South African businessman, botanist and plant collector | Lamiaceae | Bu |
| Thottea | Otto Thott (1703–1785), minister of state | Aristolochiaceae | Bu |
| Thouinia | André Thouin (1747–1824) | Sapindaceae | Qu |
| Thouinidium | André Thouin (1747–1824) | Sapindaceae | Qu |
| Threlkeldia | Caleb Threlkeld (1676–1728) | Amaranthaceae | Bu |
| Thuarea | Louis-Marie Aubert du Petit-Thouars (1758–1831) | Poaceae | Bu |
| Thulinia | Mats Thulin (b. 1948), Swedish botanist who worked at Uppsala University | Orchidaceae | Bu |
| Thunbergia | Carl Peter Thunberg (1743–1828) | Acanthaceae | Co |
| Thunia | Franz Anton von Thun-Hohenstein (1786–1873), Austrian nobleman and statesman who supported science and was knowledgeable about orchids | Orchidaceae | Bu |
| Thurnia | Everard im Thurn (1852–1932) | Thurniaceae | Bu |
| Thurovia | Frederick William Thurow (1852–1931), German-born American plant collector in Texas | Asteraceae | Bu |
| Thurya | Jean Marc Antoine Thury (1822–1905), Swiss naturalist; professor of botany at the university in Geneva | Caryophyllaceae | Bu |
| Tidestromia | Ivar Frederick Tidestrøm (1864–1956), Swedish-born American botanist in medical service in the military | Amaranthaceae | Bu |
| Tiedemannia | Friedrich Tiedemann (1781–1861) | Apiaceae | Bu |
| Tieghemella | Philippe Édouard Léon Van Tieghem (1839–1914) | Sapotaceae | Bu |
| Tietkensia | William Tietkens (1844–1933) | Asteraceae | Bu |
| Tilesia | Wilhelm Gottlieb Tilesius von Tilenau (1769–1857) | Asteraceae | Bu |
| Tilingia | Heinrich Sylvester Theodor Tiling (1818–1871) | Apiaceae | Bu |
| Tillandsia | Elias Tillandz (1640–1693) | Bromeliaceae | St |
| Tinantia | François Auguste Tinant (1803–1853), botanist in Luxembourg | Commelinaceae | St |
| Tinnea | Alexine Tinne (1835–1869), along with her mother and aunt, in honour of their African expedition in 1861 | Lamiaceae | St |
| Tirpitzia | Alfred von Tirpitz (1849–1930), admiral | Linaceae | Bu |
| Tisonia | Eugène Édouard Augustin Tison (1842–1932), French doctor and professor of botany | Salicaceae | Bu |
| Todaroa | Agostino Todaro (1818–1892) | Apiaceae | Bu |
| Tofieldia | Thomas Tofield (1730–1779), English hydrological engineer and botanist | Tofieldiaceae | Bu |
| Tolmiea | William Fraser Tolmie (1812–1886), doctor | Saxifragaceae | Co |
| Tomzanonia | Thomas A. Zanoni (b. 1949), American botanist at the New York Botanical Garden | Orchidaceae | Bu |
| Torenia | Olof Torén (1718–1753), reverend | Linderniaceae | St |
| Torralbasia | José Ildefonso Torralbas (1842–1903), Cuban botanist and agronomist; director of the university botanical museum in Havana and professor at the university | Celastraceae | Bu |
| Torreya | John Torrey (1796–1873) | Taxaceae | St |
| Torreyochloa | John Torrey (1796–1873) | Poaceae | Bu |
| Torricellia | Evangelista Torricelli (1608–1647), physicist and mathematician | Torricelliaceae | Bu |
| Touchardia | Philippe Victor Touchard (1810–1879), French vice-admiral | Urticaceae | Bu |
| Tournaya | Roland Louis Jules Alfred Tournay (1925–1972), Belgian botanist; publisher of the bulletin of the National Botanic Garden of Belgium (now the Meise Botanic Garden) | Fabaceae | Bu |
| Tournefortia | Joseph Pitton de Tournefort (1656–1708) | Heliotropiaceae | St |
| Tourneuxia | Aristide-Horace Letourneux (1820–1890), French magistrate, botanist and zoologist in Algeria, and Henri René Letourneux de la Perraudière (1831–1861), French botanist who collected in France and Algeria and on the islands of Madeira and the Canaries | Asteraceae | Bu |
| Tournonia | Dominique Jérôme Tournon (1758–1829), French doctor and botanist, botanical garden director in Toulouse | Basellaceae | Bu |
| Tourrettia | Marc Antoine Louis Claret de La Tourrette (1729–1793) | Bignoniaceae | Qu |
| Toussaintia | Léon Louis Emile Toussaint (1914–1997), Belgian botanist and agronomist | Annonaceae | Bu |
| Tovaria | Simón de Tovar, Spanish doctor and botanist | Tovariaceae | Bu |
| Townsendia | David Townsend (1787–1858), American botanist in Pennsylvania | Asteraceae | St |
| Townsonia | William Townson (1850–1926), English-born New Zealander; pharmacologist and plant collector | Orchidaceae | Bu |
| Tozzia | Bruno Tozzi (1656–1743), Italian clergyman, botanist and mycologist | Orobanchaceae | Bu |
| Tracyina | Joseph Prince Tracy (1879–1953), American botanist and plant collector | Asteraceae | Bu |
| Tradescantia | John Tradescant (1608–1662) | Commelinaceae | Co |
| Tragia | Hieronymus Bock (1498–1554), Latinised as Hieronymus Tragus | Euphorbiaceae | Bu |
| Tragiella | Hieronymus Bock (1498–1554), Latinised as Hieronymus Tragus | Euphorbiaceae | Bu |
| Tragus | Hieronymus Bock (1498–1554), Latinised as Hieronymus Tragus | Poaceae | Bu |
| Trailliaedoxa | Clementina Forrest, born Traill (1877–1937), collected this plant in Yunnan, China; wife and colleague of George Forrest | Rubiaceae | Bu |
| Trattinnickia | Leopold Trattinnick (1764–1849) | Burseraceae | Bu |
| Traubia | Hamilton Paul Traub (1890–1983) | Amaryllidaceae | Bu |
| Traunsteinera | Joseph Traunsteiner (1798–1850), Austrian apothecary and botanist | Orchidaceae | Bu |
| Trautvetteria | Ernst Rudolf von Trautvetter (1809–1889) | Ranunculaceae | St |
| Traversia | William Travers (1819–1903) | Asteraceae | Bu |
| Treculia | Auguste Trécul (1818–1896) | Moraceae | Bu |
| Treichelia | Alexander Johann August Treichel (1837–1901), German lawyer; secretary of the botanical union in Brandenburg | Campanulaceae | Bu |
| Trembleya | Abraham Trembley (1710–1784), Jean Trembley (1704–1785), Swiss mathematician, and Jacques-André Trembley (1714–1763), Swiss botanist | Melastomataceae | Qu |
| Treutlera | William John Treutler (1841–1915), British doctor who also worked at Kew Gardens | Apocynaceae | Bu |
| Trevesia | Enrichetta Treves de Bonfigli (1790–1858), Italian botanical patron, and her grandsons | Araliaceae | St |
| Trevoria | Trevor Lawrence, 2nd Baronet (1831–1913) | Orchidaceae | Bu |
| Trianaea | José Jerónimo Triana (1828–1890) | Solanaceae | Bu |
| Tribounia | Pramote Triboun (fl. 1990–2002), Thai botanist at the Thailand Institute of Scientific and Technological Research | Gesneriaceae | Bu |
| Trieenea | Elsie Elizabeth Esterhuysen (1912–2006) | Scrophulariaceae | Bu |
| Trimenia | Henry Trimen (1843–1896) | Trimeniaceae | Bu |
| Trinia | Carl Bernhard von Trinius (1778–1844) | Apiaceae | Bu |
| Triniochloa | Carl Bernhard von Trinius (1778–1844) | Poaceae | Bu |
| Tristania | Jules Marie Claude de Tristan (1776–1861), French botanist; botanical garden administrator in Orléans | Myrtaceae | St |
| Tristaniopsis | Jules Marie Claude de Tristan (1776–1861), French botanist; botanical garden administrator in Orléans | Myrtaceae | Bu |
| Triumfetta | Giovanni Battista Triumfetti (1658–1708), Italian doctor and director of the university botanical garden in Rome | Malvaceae | Bu |
| Trochetia | Henri Dutrochet (1776–1847) | Malvaceae | Bu |
| Trochetiopsis | Henri Dutrochet (1776–1847) | Malvaceae | Bu |
| Trozelia | Clas Blechert Trozelius (1719–1794), Swedish clergyman and botanist; professor of economics at Lund University | Solanaceae | Bu |
| Tryonia | Alice Faber de Tryon (1920–2009), American botanist (mainly Pteridology) | Pteridaceae | Bt |
| Tsaiorchis | Cai Xitao (1911–1981) | Orchidaceae | Qu |
| Tuctoria | anagram of Orcuttia, for Charles Russell Orcutt (1864–1929) | Poaceae | Qu |
| Tugarinovia | Arkadi Jakovlevits Tugarinov (1880–1948), Russian biologist (ornithologist), director of the museum in Krasnoyarsk | Asteraceae | Bu |
| Tulbaghia | Ryk Tulbagh (1699–1771), colonial administrator | Amaryllidaceae | Co |
| Tupeia | Tupaia (1725–1770), Polynesian navigator | Loranthaceae | Bu |
| Turczaninovia | Nikolai Turczaninow (1796–1863) | Asteraceae | Bu |
| Turgenia | Alexander Turgenev (1784–1845), historian | Apiaceae | Bu |
| Turgeniopsis | Alexander Turgenev (1784–1845), historian | Apiaceae | Bu |
| Turnera | William Turner (c. 1508 – 1568) | Passifloraceae | St |
| Turpinia | Pierre Jean François Turpin (1775–1840) | Staphyleaceae | Bu |
| Turraea | Antonio Turra (1730–1796), Italian doctor and botanist in Vicenza | Meliaceae | St |
| Turraeanthus | Antonio Turra (1730–1796), Italian doctor and botanist in Vicenza | Meliaceae | Bu |
| Turrillia | William Bertram Turrill (1890–1961) | Proteaceae | Bu |
| Tweedia | John Tweedie (1775–1862), Scottish-born Argentinian gardener and botanist | Apocynaceae | Ba |
| Tyleria | Sidney Frederick Tyler (1907–1993), American banker and cattle rancher; supporter of charitable organizations | Ochnaceae | Bu |
| Tyleropappus | Sidney Frederick Tyler (1907–1993), American banker and cattle rancher; supporter of charitable organizations | Asteraceae | Bu |
| Tzveleviochloa | Nikolai Tzvelev (1925–2015), Russian botanist, specialist in grasses and ferns | Poaceae | Bt |
| Tzvelevopyrethrum | Nikolai Tzvelev (1925–2015), Russian botanist, specialist in grasses and ferns | Asteraceae | Bu |
| Uebelinia | Johann Jakob Übelin (1793–1873), Swiss clergyman, botanical enthusiast | Caryophyllaceae | Bu |
| Uebelmannia | Werner Uebelmann (1921–2014) | Cactaceae | Bu |
| Uittienia | Hendrik Uittien (1898–1944), Dutch botanist, curator in Utrecht and Deventer | Fabaceae | Bu |
| Uleanthus | Ernst Heinrich Georg Ule (1854–1915) | Fabaceae | Qu |
| Ulearum | Ernst Heinrich Georg Ule (1854–1915) | Araceae | Qu |
| Uleiorchis | Ernst Heinrich Georg Ule (1854–1915) | Orchidaceae | Qu |
| Uleophytum | Ernst Heinrich Georg Ule (1854–1915) | Asteraceae | Qu |
| Ulleria | Jean Ruel (1474–1537) | Acanthaceae | Bu |
| Ungeria | Franz Unger (1800–1870) | Malvaceae | Bu |
| Ungernia | Franz Ungern-Sternberg (1808–1885), Baltic German botanist and doctor in Turin, Italy | Amaryllidaceae | Bu |
| Ungnadia | David Ungnad von Sonnegg (1530–1600), ambassador | Sapindaceae | St |
| Urbanodendron | Ignatz Urban (1848–1931) | Lauraceae | Bu |
| Urbinella | Manuel Urbina y Altamirano (1843–1906), Mexican doctor, apothecary, botanist and zoologist | Asteraceae | Bu |
| Uribea | Antonio Lorenzo Uribe Uribe (1900–1980), Colombian clergyman, botanist and zoologist, and his father Joachim Antonio Uribe (1858–1935), Colombian instructor and naturalist | Fabaceae | Bu |
| Urmenetea | Hieronymus Urmeneta (1816–1881), Chilean administrator; agricultural society president | Asteraceae | Bu |
| Uroskinnera | George Ure Skinner (1804–1867), English merchant, ornithologist and plant collector | Plantaginaceae | Bu |
| Ursinia | Johannes Heinrich Ursinus (1608–1667) | Asteraceae | St |
| Urvillea | Jules Dumont d'Urville (1790–1842) | Sapindaceae | Bu |
| Usteria | Paul Usteri (1768–1831) | Loganiaceae | Bu |
| Utleya | Kathleen Burt-Utley (b. 1944) and her husband John F. Utley (b. 1944), American botanists at the University of Florida and the University of New Orleans | Ericaceae | Bu |
| Uvedalia | Robert Uvedale (1642–1722) | Phrymaceae | Bu |
| Vachellia | George Harvey Vachell (1799–1839), clergyman | Fabaceae | Qu |
| Vahlia | Martin Vahl (1749–1804) | Vahliaceae | Qu |
| Vahlodea | Jens Vahl (1796–1854) | Poaceae | Bu |
| Vailia | Anna Murray Vail (1863–1955) | Apocynaceae | Bu |
| Valantia | Sébastien Vaillant (1669–1722) | Rubiaceae | Bu |
| Valdivia | Pedro de Valdivia (1497–1553), conquistador | Escalloniaceae | Bu |
| Vallea | Felice Spirito Valle (1715–1747), Italian military doctor and botanist; collected in the Alps and on Corsica | Elaeocarpaceae | Bu |
| Vallesia | Francisco Vallés (1524–1592), doctor | Apocynaceae | Bu |
| Vallisneria | Antonio Vallisneri (1661–1730) | Hydrocharitaceae | St |
| Vancouveria | George Vancouver (1758–1798), explorer | Berberidaceae | Co |
| Vandasina | Karel Vandas (1861–1923), Bohemian-born Czech botanist and teacher in Prague | Fabaceae | Bu |
| Vandellia | Domenico Vandelli (1735–1816) | Linderniaceae | Bu |
| Vanheerdea | Pieter van Heerde (1893–1979), South African teacher and plant collector | Aizoaceae | Bu |
| Vanhouttea | Louis van Houtte (1810–1876) | Gesneriaceae | Bu |
| Vanoverberghia | Morice Vanoverbergh (1885–1987), Belgian clergyman and amateur botanist | Zingiberaceae | Bu |
| Van-royena | Pieter van Royen (1923–2002) | Sapotaceae | Bu |
| Vanwykia | Pieter van Wyck (1931–2006), South African botanist and ecologist | Loranthaceae | Bu |
| Vanzijlia | Dorothy Constantia van Zijl (1886–1938), South African plant collector | Aizoaceae | Bu |
| Vargasiella | Julio César Vargas Calderón (1903–2002), Peruvian naturalist, professor of botany and director of the botanical museum in Cusco | Orchidaceae | Bu |
| Varronia | Marcus Terentius Varro (116–27 BC), polymath and writer | Boraginaceae | Bu |
| Vasconcellea | Simão de Vasconcelos (1597 – c. 1672), Brazilian clergyman, historian and writer | Caricaceae | Bu |
| Vaseyochloa | George Vasey (1822–1893) | Poaceae | Qu |
| Vasqueziella | Roberto Vásquez (1941–2015), Bolivian naturalist, professor of botany, specialist in Bolivian orchids | Orchidaceae | Bu |
| Vateria | Abraham Vater (1684–1751) | Dipterocarpaceae | Bu |
| Vateriopsis | Abraham Vater (1684–1751) | Dipterocarpaceae | Bu |
| Vatovaea | Aristocle Vatova (1897–1992), Italian botanist (with a focus on algae) in Rovinj | Fabaceae | Bu |
| Vatricania | Louis Félix Vatrican (1904–2007), agricultural engineer from Monaco, director of the national Jardin Exotique | Cactaceae | Bu |
| Vauquelinia | Louis Nicolas Vauquelin (1763–1829) | Rosaceae | Bu |
| Vavilovia | Nikolai Vavilov (1887–1943) | Fabaceae | Bu |
| Veitchia | James Veitch Jr. (1815–1869) and his son John Gould Veitch | Arecaceae | St |
| Velascoa | José María Velasco Gómez (1840–1912), painter and naturalist | Crossosomataceae | Bu |
| Veldkampia | Jan Frederik Veldkamp (1941-2017) | Poaceae | Bt |
| Velleia | Thomas Velley (1748–1806) | Goodeniaceae | Bu |
| Vellosiella | José Mariano de Conceição Vellozo (1742–1811) | Orobanchaceae | Bu |
| Vellozia | Joaquim Velloso de Miranda (1733–1815), Brazilian clergyman and plant collector | Velloziaceae | Bu |
| Veltheimia | August Ferdinand von Veltheim (1741–1801) | Asparagaceae | St |
| Venegasia | Miguel Venegas (1680–1764) | Asteraceae | Bu |
| Ventenata | Étienne Pierre Ventenat (1757–1808) | Poaceae | Bu |
| Verdesmum | Bernard Verdcourt (1925–2011) | Fabaceae | Bu |
| Verhuellia | Quirijn Maurits Rudolph Ver Huell (1787–1860), Dutch rear admiral, illustrator and entomologist | Piperaceae | Bu |
| Vernonanthura | William Vernon (1666 or 1667 – c. 1713), English plant collector; collected in the US state of Maryland for the Royal Society | Asteraceae | Bu |
| Vernonia | William Vernon (1666 or 1667 – c. 1713), English plant collector; collected in the US state of Maryland for the Royal Society | Asteraceae | Co |
| Vernoniopsis | William Vernon (1666 or 1667 – c. 1713), English plant collector; collected in the US state of Maryland for the Royal Society | Asteraceae | Qu |
| Verreauxia | Jules Verreaux (1807–1873) | Goodeniaceae | Bu |
| Verschaffeltia | Ambroise Verschaffelt (1825–1886) | Arecaceae | St |
| Vesalea | Andreas Vesalius (1514–1564), Belgian anatomist and physician to Charles V, Holy Roman Emperor | Caprifoliaceae | Bt |
| Veselskya | Friedrich Veselský (1813–1866), Bohemian lawyer in present-day Prešov; amateur botanist with a focus on mushrooms | Brassicaceae | Bu |
| Vesper | Fengjie Sun (b. 1968) and Stephen Roy Downie (b. 1959), American botanists and evolutionary biologists in Georgia | Apiaceae | Bu |
| Vesselowskya | E. Vesselowsky, Russian scientist from Saratov | Cunoniaceae | Bu |
| Vestia | Lorenz Chrysanth von Vest (1776–1840) | Solanaceae | Co |
| Veyretella | Yvonne Veyret (b. 1925), French botanist and plant collector at the National Museum of Natural History; specialist in orchids | Orchidaceae | Bu |
| Veyretia | Yvonne Veyret (b. 1925), French botanist and plant collector at the National Museum of Natural History; specialist in orchids | Orchidaceae | Bu |
| Vicatia | Philippe-Rodolphe Vicat (1742–1783), Swiss doctor and botanist in Warsaw, Poland, and Lausanne | Apiaceae | Bu |
| Vicoa | Giambattista Vico (1668–1744), philosopher | Asteraceae | Bu |
| Victoria | Queen Victoria (1819–1901) | Nymphaeaceae | St |
| Vidalasia | Jules Eugène Vidal (1914 – after 2016), French botanist at the National Museum of Natural History; specialist in the flora of Southeast Asia | Rubiaceae | Bu |
| Vieraea | José de Viera y Clavijo (1731–1813) | Asteraceae | Bu |
| Vigna | Dominico Vigna (d. 1647), Italian botanist | Fabaceae | St |
| Viguiera | Louis Guillaume Alexandre Viguier (1790–1867), French doctor and botanist from Montpellier | Asteraceae | Bu |
| Viguieranthus | René Viguier (1880–1931) | Fabaceae | Bu |
| Viguierella | René Viguier (1880–1931) | Poaceae | Bu |
| Villadia | Manuel Maria Villada (1841–1924), Mexican mineralogist, geologist and paleobotanist | Crassulaceae | Bu |
| Villanova | Tomás Manuel Vilanova Muñoz y Poyanos (1737–1802), Spanish doctor and botanist; professor of botany and chemistry at the University of Valencia | Asteraceae | Bu |
| Villaria | Celestino Fernández-Villar (1838–1907) | Rubiaceae | Bu |
| Villarsia | Dominique Villars (1745–1814) | Menyanthaceae | St |
| Villasenoria | José Luis Villaseñor (b. 1954), Mexican professor of botany in Mexico City; specialist in New World tropical flora | Asteraceae | Bu |
| Virgilia | Virgil (70–19 BC), poet | Fabaceae | St |
| Viridivia | Percy James Greenway (1897–1980), South African botanist at the agricultural research station and herbarium in Nairobi, Kenya | Passifloraceae | Bu |
| Virotia | Robert Virot (1915–2002) | Proteaceae | Bu |
| Viscainoa | Sebastián Vizcaíno (1548 – c. 1625), military officer and explorer | Zygophyllaceae | Qu |
| Vismia | Gérard de Visme (c. 1725 – c. 1797), French and English merchant in Lisbon, Portugal | Hypericaceae | Bu |
| Vismianthus | Gérard de Visme (c. 1725 – c. 1797), French and English merchant in Lisbon, Portugal | Connaraceae | Bu |
| Visnea | Gérard de Visme (c. 1725 – c. 1797), French and English merchant in Lisbon, Portugal | Pentaphylacaceae | Bu |
| Vitekorchis | Ernst Vitek (b. 1953), Austrian botanist at the museum of natural history in Vienna | Orchidaceae | Bu |
| Vittadinia | Carlo Vittadini (1800–1865) | Asteraceae | St |
| Vittetia | Nelly Elsa Vittet (d. 1995), Argentinian botanist at the natural science museum in Buenos Aires | Asteraceae | Bu |
| Viviania | Domenico Viviani (1772–1840) | Francoaceae | Bu |
| Vlokia | Johannes Hendrik Jacobus Vlok (b. 1957), forester in South Africa | Aizoaceae | Bu |
| Volkameria | Johann Georg Volkamer, the Younger (1662–1744), German doctor and botanist in Nuremberg | Lamiaceae | Bu |
| Volkensinia | Georg Volkens (1855–1917) | Amaranthaceae | Bu |
| Vossia | Johann Heinrich Voss (1751–1826), classicist | Poaceae | Bu |
| Votschia | Oskar Hermann Wilhelm Votsch (1879–1927), German botanist and teacher in Delitzsch | Primulaceae | Bu |
| Vriesea | Willem Hendrik de Vriese (1806–1862) | Bromeliaceae | St |
| Vrydagzynea | Theodor Daniel Vrydag or Vrydag Zijnen (1799–1863), Dutch apothecary from The Hague; wrote about Cinchona | Orchidaceae | Bu |
| Vulpiella | Johann Samuel Vulpius (1760–1846), German apothecary in Stuttgart and Pforzheim | Poaceae | Bu |
| Vvedenskya | Aleksai Ivanovich Vvedensky (1898–1972), Russian botanist at herbariums in Penza and Tashkent | Apiaceae | Bu |
| Wachendorfia | Evert Jacob van Wachendorff (1702–1758), Dutch botanist | Haemodoraceae | St |
| Wahlenbergia | Göran Wahlenberg (1780–1851) | Campanulaceae | St |
| Waitzia | Karl Friedrich Waitz (1774–1848), German botanist and agronomist in Saxe-Altenburg | Asteraceae | Bu |
| Waldsteinia | Franz de Paula Adam von Waldstein (1759–1823) | Rosaceae | Co |
| Wallacea | Alfred Russel Wallace (1823–1913) | Ochnaceae | Bu |
| Wallaceodendron | Alfred Russel Wallace (1823–1913) | Fabaceae | Bu |
| Wallenia | Mathew Wallen (18th century), Irish naval officer and botanical enthusiast; raised native and exotic plants near Kingston, Jamaica | Primulaceae | Qu |
| Walleria | Horace Waller (1833–1896) | Tecophilaeaceae | Bu |
| Wallichia | Nathaniel Wallich (1786–1854) | Arecaceae | St |
| Wallisia | Gustav Wallis (1830–1878) | Bromeliaceae | Bu |
| Walteranthus | Hans Paul Heinrich Walter (b. 1882), German botanist who worked with Adolf Engler | Gyrostemonaceae | Bu |
| Waltheria | Augustin Friedrich Walther (1688–1746) | Malvaceae | Qu |
| Waltillia | Walter Till (b. 1956), Austrian botanist, herbarium director in Vienna | Bromeliaceae | Bu |
| Walwhalleya | Ralph Derwyn Broughton Whalley (b. 1933), American botanist; specialist in grasses | Poaceae | Bu |
| Wangenheimia | Friedrich Adam Julius von Wangenheim (1749–1800) | Poaceae | Bu |
| Warburgia | Otto Warburg (1859–1938) | Canellaceae | Bu |
| Warczewiczella | Józef Warszewicz (1812–1866) | Orchidaceae | St |
| Warionia | Adrien Warion (1837–1880) | Asteraceae | Bu |
| Warmingia | Eugenius Warming (1841–1924) | Orchidaceae | Bu |
| Warneckea | Otto Warnecke (b. c. 1873), German gardener and plant collector in German East Africa (roughly present-day Tanzania) and Ballenstedt | Melastomataceae | Bu |
| Warnockia | Barton Holland Warnock (1911–1998) | Lamiaceae | Bu |
| Warrea | Frederick James Warre (1798–1872), English businessman, mining association director in Rio de Janeiro; collected orchids | Orchidaceae | Bu |
| Warreella | Frederick James Warre (1798–1872), English businessman, mining association director in Rio de Janeiro; collected orchids | Orchidaceae | Bu |
| Warreopsis | Frederick James Warre (1798–1872), English businessman, mining association director in Rio de Janeiro; collected orchids | Orchidaceae | Bu |
| Warszewiczia | Józef Warszewicz (1812–1866) | Rubiaceae | Bu |
| Washingtonia | George Washington (1732–1799), president of the United States | Arecaceae | Co |
| Watsonia | William Watson (1715–1787) | Iridaceae | Co |
| Weberbauera | Augusto Weberbauer (1871–1948) | Brassicaceae | Qu |
| Weberbauerella | Augusto Weberbauer (1871–1948) | Fabaceae | Qu |
| Weberbauerocereus | Augusto Weberbauer (1871–1948) | Cactaceae | Qu |
| Weberocereus | Frédéric Albert Constantin Weber (1830–1903) | Cactaceae | Bu |
| Weddellina | Hugh Algernon Weddell (1819–1877) | Podostemaceae | Bu |
| Wedelia | Georg Wolfgang Wedel (1645–1721) | Asteraceae | St |
| Weigela | Christian Ehrenfried Weigel (1748–1831) | Caprifoliaceae | Co |
| Weinmannia | Johann Wilhelm Weinmann (1683–1741) | Cunoniaceae | St |
| Welchiodendron | Marcus Baldwin Welch (1895–1942), New Zealand botanist and chemist in the sugar industry, in munitions manufacturing in Scotland, and in other jobs in Australia | Myrtaceae | Bu |
| Weldenia | Ludwig von Welden (1780–1853), army officer | Commelinaceae | St |
| Welfia | George V of Hanover (1819–1878) | Arecaceae | Bu |
| Wellstedia | James Raymond Wellsted (1805–1842), naval officer | Boraginaceae | Bu |
| Welwitschia | Friedrich Welwitsch (1806–1872) | Welwitschiaceae | Ch |
| Welwitschiella | Friedrich Welwitsch (1806–1872) | Asteraceae | Bu |
| Wenchengia | Wen Chen Wu (1898–1942), Chinese professor of botany with a focus on Chinese flora | Lamiaceae | Bu |
| Wendlandia | Heinrich Wendland (1792–1869) and possibly Johann Christoph Wendland (1755–1828) | Rubiaceae | Bu |
| Wendlandiella | Heinrich Wendland (1792–1869) | Arecaceae | Bu |
| Wenzelia | Chester A. Wenzel (1882–1929), American teacher, cattle rancher and plant collector in the Philippines | Rutaceae | Bu |
| Werauhia | Werner Rauh (1913–2000) | Bromeliaceae | Bu |
| Wercklea | Karl Wercklé (1860–1924), French-Lorrainer and Costa Rican gardener and botanist; also worked in the United States | Malvaceae | Bu |
| Werneria | Abraham Gottlob Werner (1749–1817) | Asteraceae | Bu |
| Westoniella | Arthur Stewart Weston (b. 1932), American botanist with a focus on Costa Rican plants | Asteraceae | Qu |
| Westringia | Johan Peter Westring (1753–1833), Swedish physician and lichenologist | Lamiaceae | St |
| Wetria | Christoph Jacob Trew (1695–1769) | Euphorbiaceae | Bu |
| Wettinia | Frederick Augustus I of Saxony (1750–1827) | Arecaceae | Bu |
| Wettsteiniola | Richard Wettstein (1863–1931) | Podostemaceae | Bu |
| Whipplea | Amiel Weeks Whipple (1818–1863), military officer | Saxifragaceae | Bu |
| Whiteochloa | Cyril Tenison White (1890–1950) | Poaceae | Bu |
| Whiteodendron | Cyril Tenison White (1890–1950) | Myrtaceae | Bu |
| Whitesloanea | Alain Campbell White (1880–1951), American botanist, and Boyd Lincoln Sloane (1885–1955), American botanist | Apocynaceae | Bu |
| Whitfieldia | Thomas Whitfield, plant and animal collector in the 1840s in West Africa | Acanthaceae | Bu |
| Whitfordiodendron | Harry Nichols Whitford (1872–1941), American forester and professor of tropical forestry at Yale University | Fabaceae | Bu |
| Whitmorea | Timothy Charles Whitmore (1935–2002), English ecologist, botanist, geologist and climatologist | Stemonuraceae | Bu |
| Whittonia | Brian Alan Whitton (b. 1935), English botanist at Durham University | Peridiscaceae | Bu |
| Whytockia | James Whytock (1845–1926), English gardener in Ireland and at various Scottish castles and estates; president of the Scottish Horticultural Association and the Botanical Society of Edinburgh | Gesneriaceae | Bu |
| Wiborgia | Erik Viborg (1759–1822) | Fabaceae | Bu |
| Wiborgiella | Erik Viborg (1759–1822) | Fabaceae | Bt |
| Widdringtonia | Samuel Edward Cook (1787–1856) | Cupressaceae | Bu |
| Wielandia | Joseph Fridolin Wieland (1804–1872), German-born Swiss botanist and doctor in Aargau | Phyllanthaceae | Bu |
| Wiesneria | Julius Wiesner (1838–1916) | Alismataceae | Bu |
| Wigandia | Johann Wigand (1523–1587), bishop | Hydrophyllaceae | St |
| Wightia | Robert Wight (1796–1872) | Paulowniaceae | Qu |
| Wikstroemia | Johan Emanuel Wikström (1789–1856) | Thymelaeaceae | Ba |
| Wilbrandia | Johann Bernhard Wilbrand (1779–1846) | Cucurbitaceae | Bu |
| Wilhelmsia | Wilhelms, Russian botanist; collected plants in Georgia | Caryophyllaceae | Bu |
| Wilkesia | Charles Wilkes (1798–1877), naval officer | Asteraceae | Bu |
| Wilkiea | David Elliott Wilkie (1815–1885), Scottish-born Australian doctor in Melbourne; vice-president of what is now the Royal Society of Victoria | Monimiaceae | Bu |
| Willdenowia | Carl Ludwig Willdenow (1765–1812) | Restionaceae | Bu |
| Willemetia | Pierre Rémi Willemet (1735–1807), French botanist, professor of natural history and botanical garden director in Nancy | Asteraceae | Bu |
| Williamodendron | William Antônio Rodrigues (b. 1928) | Lauraceae | Bu |
| Willisia | John Christopher Willis (1868–1958) | Podostemaceae | Bu |
| Willkommia | Heinrich Moritz Willkomm (1821–1895) | Poaceae | Bu |
| Willughbeia | Francis Willughby (1635–1672) | Apocynaceae | Bu |
| Wilsonia | John Wilson (1696–1751), English shoemaker, baker and botanist | Convolvulaceae | Bu |
| Wimmerella | Franz Elfried Wimmer (1881–1961), Austrian clergyman and botanist; professor of natural history in Istanbul, Turkey; Viennese priest; specialist in Lobeliaceae | Campanulaceae | Bu |
| Wimmeria | Christian Friedrich Heinrich Wimmer (1803–1868) | Celastraceae | Bu |
| Windsorina | George V (1865–1936) and the House of Windsor | Rapateaceae | Bu |
| Winifredia | Winifred Curtis (1905–2005) | Restionaceae | Bu |
| Winklerella | Hubert Winkler (1875–1941) | Podostemaceae | Bu |
| Wintera | John Winter (16th century), one of the ship captains of Francis Drake's circumnavigation | Winteraceae | Bu |
| Wisteria | Caspar Wistar (1761–1818), doctor | Fabaceae | Co |
| Withania | Henry Witham (1779–1844) | Solanaceae | Qu |
| Witheringia | William Withering (1741–1799) | Solanaceae | Bu |
| Witsenia | Nicolaes Witsen (1641–1717), statesman and writer | Iridaceae | Bu |
| Wittmackanthus | Ludwig Wittmack (1839–1929) | Rubiaceae | Bu |
| Wittmackia | Ludwig Wittmack (1839–1929) | Bromeliaceae | Bu |
| Wittsteinia | Georg Christian Wittstein (1810–1887) | Alismataceae | Bu |
| Wodyetia | Wodyeti (c. 1900 – 1978), Aboriginal Australian who first reported on this palm genus | Arecaceae | Bu |
| Wolffia | Johann Friedrich Wolff (1778–1806) | Araceae | Qu |
| Wolffiella | Johann Friedrich Wolff (1778–1806) | Araceae | Qu |
| Wollastonia | William Hyde Wollaston (1766–1828), chemist | Asteraceae | Bu |
| Woodburnia | John Woodburn (1843–1902), colonial administrator | Araliaceae | Bu |
| Woodfordia | John Alexander Woodford (fl. 1790s), English lawyer who maintained a large greenhouse in Vauxhall | Lythraceae | Bu |
| Woodia | John Medley Wood (1827–1915) | Apocynaceae | Bu |
| Wooleya | Charles Hugh Frederick Wooley (1894–1969), English naval officer, natural scientist and citrus grower; supplied Kirstenbosch National Botanical Garden with succulents from around South Africa | Aizoaceae | Bu |
| Woollsia | William Woolls (1814–1893) | Ericaceae | Bu |
| Worsleya | Arthington Worsley (1861–1944) | Amaryllidaceae | St |
| Wrightia | William Wright (1735–1819) | Apocynaceae | Bu |
| Wulfenia | Franz Xaver von Wulfen (1728–1805) | Plantaginaceae | St |
| Wulfeniopsis | Franz Xaver von Wulfen (1728–1805) | Plantaginaceae | Qu |
| Wullschlaegelia | Heinrich Wullschlägel (1805–1864) | Orchidaceae | Bu |
| Wunderlichia | Christian Karl Wunderlich (1778–1855), German-born Russian apothecary's assistant, teacher, botanist, office worker and organist in present-day Volgograd; built up a herbarium | Asteraceae | Bu |
| Wurdastom | John Julius Wurdack (1921–1998), American botanist at the New York Botanical Garden and the Smithsonian Institution | Melastomataceae | Bu |
| Wurfbainia | Johann Siegmund Wurffbain (1613–1661), German traveler in the service of the Dutch East India Company as a soldier and merchant; also a councilman in Nuremberg | Zingiberaceae | Bu |
| Wurmbea | Friedrich von Wurmb (1742–1781) | Colchicaceae | Bu |
| Wydleria | Heinrich Wydler (1800–1883) | Apiaceae | Bu |
| Wyethia | Nathaniel Jarvis Wyeth (1802–1856), businessman and explorer | Asteraceae | St |
| Xatardia | Barthélemy Joseph Paul Xatard (1774–1846), French apothecary and botanist who collected in the eastern Pyrenees | Apiaceae | Bu |
| Ximenia | Francisco Ximénez (d. 1620), Spanish clergyman and naturalist (botanist), missionary in Spanish Florida | Olacaceae | Bu |
| Yabea | Yoshitaka Yabe (1876–1931), Japanese professor of botany at the College of Arts and Sciences in Tokyo | Apiaceae | Bu |
| Yeatesia | William Smith Yeates (1856–1908), American geologist, professor in Georgia; collected along the Flint River | Acanthaceae | Bu |
| Yoania | Udagawa Yōan (1798–1846), chemist and translator | Orchidaceae | Bu |
| Youngia | Edward Young (1684–1765), poet, and Thomas Young (1773–1829), scientist | Asteraceae | Bu |
| Yvesia | Alfred Marie Augustin Saint-Yves (1855–1933), French soldier and botanist who settled in Nice and focused on grasses | Poaceae | Bu |
| Zabelia | Hermann Zabel (1832–1912) | Caprifoliaceae | Bu |
| Zaluzania | Adam Zalužanský ze Zalužan (1558–1613), Bohemian botanist and doctor in Prague; also taught at Charles University | Asteraceae | Bu |
| Zaluzianskya | Adam Zalužanský ze Zalužan (1558–1613), Bohemian botanist and doctor in Prague; also taught at Charles University | Scrophulariaceae | Co |
| Zandera | Robert Zander (1892–1969), German botanist and horticulturist in Berlin | Asteraceae | Bu |
| Zannichellia | Gian Girolamo Zannichelli (1661–1729), Italian apothecary and natural scientist in Venice | Potamogetonaceae | Bu |
| Zanonia | Giacomo Zanoni (1615–1682), Italian botanist, botanical garden director in Bologna | Cucurbitaceae | Bu |
| Zantedeschia | Giovanni Zantedeschi (1773–1846) | Araceae | Co |
| Zehnderia | Alfons Zehnder (1920–1985), Swiss teacher and botanist in Wettingen with a focus on algae | Podostemaceae | Bu |
| Zehneria | Josef Zehner (19th century) | Cucurbitaceae | Bu |
| Zelenkoa | Harry Zelenko (b. 1928), American marketing designer and orchid grower | Orchidaceae | Bu |
| Zeltnera | Louis Zeltner (b. 1938) and his wife Nicole Zeltner (b. 1934), Swiss botanists with a focus on Gentianaceae | Gentianaceae | Bu |
| Zenia | H. C. Zen, scientist and government official | Fabaceae | Bu |
| Zenkerella | Georg August Zenker (1855–1922) | Fabaceae | Bu |
| Zenkeria | Jonathan Carl Zenker (1799–1837) | Poaceae | Bu |
| Zenobia | Zenobia (b. c. 240), queen | Ericaceae | Co |
| Zexmenia | José Mariano Jiménez (1781–1811), independence fighter | Asteraceae | Bu |
| Zeyheria | Johann Michael Zeyher (1770–1843) | Bignoniaceae | Bu |
| Zieria | John Zier (d. 1793), Polish and English apothecary and botanist, specialist in spore-bearing plants | Rutaceae | Bu |
| Zingeria | Vasili Yakovlevich Zinger (1836–1907) | Poaceae | Bu |
| Zinnia | Johann Gottfried Zinn (1727–1759) | Asteraceae | Co |
| Zinowiewia | Paul Zinowiew, botanist, curator at the university in present-day Kharkiv, Ukraine | Celastraceae | Bu |
| Zippelia | Alexander Zippelius (1797–1828) | Piperaceae | Bu |
| Zizia | Johann Baptist Ziz (1779–1829) | Apiaceae | Bu |
| Zizkaea | Georg Zizka (b. 1955), German evolutionary botanist; specialist in Bromeliaceae | Bromeliaceae | Bu |
| Zoegea | Johan Zoëga (1742–1788) | Asteraceae | Bu |
| Zollernia | Frederick William III of Prussia (1770–1840) | Fabaceae | Bu |
| Zollingeria | Heinrich Zollinger (1818–1859) | Sapindaceae | Bu |
| Zornia | Johannes Zorn (1739–1799) | Fabaceae | Bu |
| Zosima | Nikolaos Zosima (1758–1842), Anastasios Zosima (1754–1828) and Zois Zosima (1764–1828), Greek-Russian brothers and merchants in Moscow who supported naturalists | Apiaceae | Bu |
| Zotovia | Victor Zotov (1908–1977) | Poaceae | Bu |
| Zoysia | Karl von Zois (1756–1800) | Poaceae | St |
| Zuccagnia | Attilio Zuccagni (1754–1807), Italian botanist | Fabaceae | Bt |
| Zuccarinia | Joseph Gerhard Zuccarini (1797–1848) | Rubiaceae | Bt |
| Zuloagaea | Fernando Omar Zuloaga (b.1951), Argentinian botanist and Professor of Phytogeography from the National University of La Plata | Poaceae | Bt |
| Zuloagocardamum | Fernando Omar Zuloaga (b.1951), Argentinian botanist and Professor of Phytogeography from the National University of La Plata | Brassicaceae | Bt |
