Endemic families of Madagascar. III. A synoptic revision of Schizolaena (Sarcolaenaceae)

As part of an assessment of the conservation status of the vascular plant families endemic to Madagascar and the Comoro Islands, a synoptic revision is presented of Schizolaena (Sarcolaenaceae). Recent molecular sequence data indicate that Sarcolaenaceae are sister to Dipterocarpaceae in an expanded Malvales. Within the family, Schizolaena appears closest to Rhodolaena: both have a greatly expanded involucre in fruit enclosing (1-)2 sessile flowers with numerous stamens, but Schizolaena has only 3 sepals and branched inflorescences versus 5 sepals and a single pair of flowers borne on a long peduncle in Rhodolaena. Study of available herbarium material allows the recognition of 18 species, eight of which are described as new (S. capuronii, S. cavacoana, S. gereaui, S. manomboensis, S. masoalensis, S. milleri, S. tampoketsana, and S. turkii). A key to the species is provided in English and French.