Dracoscirpoides (Cyperaceae) - a new genus from Southern Africa, its taxonomy and floral ontogeny.

摘要

A new genus, Dracoscirpoides Muasya, is described and illustrated. This genus accommodates two southern African species, Scirpus falsus and S. ficinioides, until now included in the holarctic Scirpus (Scirpeae) due to the presence of perianth parts. Recent molecular phylogenetic studies have established that these species form a clade closer to Scirpoides and Hellmuthia within the Isolepis/Ficinia clade (Cypereae). We present floral developmental data focussing on the origin of the perianth parts (bristles) in these species, and discuss the utility of this character in generic delimitation. Cypereae are diagnosed by the presence of a Cyperus-type embryo and by the absence of perianth parts, except in the genera Dracoscirpoides and Hellmuthia. We describe a third species in the genus, Dracoscirpoides surculosa, diagnosed by its surculose underground stem and more northerly distribution.