Revision of Seriphium plumosum (Gnaphalieae: Asteraceae) in southern Africa with description of new species in Seriphium

Abstract

Seriphium plumosum L. from southern Africa has been shown to comprise at least seven distinct species based on analysis of morphological, environmental, and multilocus DNA sequence data. On that evidence, Stoebe burchellii Levyns, Stoebe virgata Thunb., and Stoebe vulgaris Levyns are reinstated in Seriphium, and four new species are described, viz., Seriphium alto-argillaceum Z.Shaik, Se. burrowsii Z.Shaik, Se. crypticum Z.Shaik, and Se. dunensis Z.Shaik. Four of these species are endemic to the Cape Floristic Region of South Africa, and one is so far known from a single high-elevation locality. We present a key to species in the Seriphium plumosum complex, and for each species provide a formal description with accompanying images, typification and synonymy, with distribution maps based on verified field-collected and herbarium specimens.