Molecular and morphological notes on Opuntia ser. Streptacanthae (Cactaceae)

A detailed morphological and molecular study of the four Opuntia species belonging to the ser. Streptacanthae is carried out. No published phylogenetic study of Opuntia includes these four species. Our data support the recognition of the four taxa as separated species but related by the characteristic of having a glabrous epidermis, yellow flowers, red and sweet fruits, in the present study it is recovered forming a monophyletic group within Opuntia s.str.