text: Description Caltha palustris is a  high, hairless, fleshy, perennial, herbaceous plant that dies down in autumn and overwinters with buds near the surface of the marshy soil. The plants have many,  thick strongly branching roots. Its flowering stems are hollow, erect or more or less decumbent. The alternate true leaves are in a rosette, each of which consist of a leaf stem that is about four times as long as the kidney-shaped leaf blade, itself between  long and  wide, with a heart-shaped foot, a blunt tip, and a scalloped to toothed, sometime almost entire margin particularly towards the tip. In their youth the leaves are protected by a membranous sheath, that may be up to  long in fully grown plants.
  Inflorescence
  The common marsh-marigold mostly has several flowering stems of up to  long, carrying mostly several seated leaflike stipules, although lower ones may be on a short petiole; and between four and six (but occasionally as few as one or as many as 25) flowers. The flowers are approximately  but range between  in diameter. There are four to nine (mostly five) petal-like, brightly colored (yolk yellow, white or magenta), inverted egg-shaped sepals, each about  but ranging from  long, and about , ranging from  wide; they have a blunt or sometimes acute tip. Real petals and nectaries are lacking. Between 50 and 120 stamens with flattened yellow filaments and yellow tricolpate or sometimes pantoporate pollen encircle 5–25 free, flattened, linear-oblong, yellow to green carpels, with a two-lobed, obliquely positioned stigma, and each with many seedbuds. This later develops into a seated, funnel-shaped fruit (a so-called follicle) of  long and  wide, that opens with one suture at the side of the axis and contains 7–20 ovoid, brown to black seeds of about .
  Taxonomy