Two New Species of Philodendron (Araceae) from Central Brazil

Central Brazil is a large area of middle-altitude uplands, with an intermediate rainfall (900 1400 mm/yr) and a marked dry season between May and September. Most of the area is covered with cerrado vegetation, a savanna-like formation that does not seem to be suitable for aroids in general. In fact, only very few aroids (if any) could survive on the oligotrophic soil of cerrado (or as epiphytic herbs) which may explain why most aroid specialists have not conducted intensive studies there. However, there are some interesting vegetation formations that hold a considerable number of aroid species within the cerrado province, such as seasonal marshes, gallery forests, montane vegetation (campos rupestres) and limestone outcrops. These vegetation formations have been poorly studied, and undoubtedly contain a significant number of new taxa, besides the two species here described for the first time. The present paper describes two new species of Philodendron, the second largest genus of the family Araceae with approximately 500 species recognised at present (Mayo et al. 1997). Both taxa occur near the Brazilian capital, Brasilia. This is regarded as one of the botanically best known areas of Central Brazil, and so their discovery suggests that even here a great deal of botanical collecting is still clearly needed.