A Synopsis of Neotropical Plukenetia (Euphorbiaceae) Including Two New Species

A synopsis of the eleven neotropical species of Plukenetia (Euphorbiaceae) is given. The genus Plukenetia is redefined to include the neotropical monotypic genera Eleutherostigma and Vigin (previously known as Fragariopsis). As treated here Plukenetia may be distinguished from all other members of the tribe Plukenetieae by its four-carpellate ovary. Two new species, P. supraglandulosa from French Guiana and the Brazilian state of Amapa and P. stipellata from Mexico and Central America, are described and illustrated. Plukenetia supraglandulosa is closely allied with P. penninervia and P. multiglandulosa and differs in the presence of scattered laminar glands on the upper leaf surface and longer inflorescences. The three species share a very similar androecium of dimorphic stamens, which is correctly described for the first time. Plukenetia stipellata differs from the closely related South American and West Indian species, P. volubilis, by its stipellate leaf blade base, shorter styles and longer slender stamens. Two new combinations, P. serrata and P. lehmanniana, are proposed. A key to the 11 species in the Neotropics is provided.