Two new species of Begonia sect. Erminea (begoniaceae) from nosy mangabe in Madagascar

Abstract

Begonia nosymangabensis Scherber. & Duruiss. and Begonia pteridoides Scherber. & Duruiss. are described and illustrated. Both new species belong to Begonia sect. Erminea A. D C. Begonia nosymangabensis is compared to Begonia keraudreniae Bosser, from which it differs in having larger and more deeply incised leaves which lack adaxial hairs. Begonia pteridoides is related to Begonia bogneri Ziesenh. but differs by its very divided leaves. Both new species are micro-endemics, restricted to Nosy Mangabe island in northeast Madagascar and are assessed as "Vulnerable" according to the IUCN Red List Categories and Criteria.