Leaf anatomy of the South African Danthonieae (Poaceae). VI. Merxmuellera arundinacea and M. cincta

Abstract

The leaf blade anatomy and the abaxial epidermal histology of Merxmuellera arundinacea (Berg.) Conert and M. cincta (Nees) Conert are described and illustrated. These two species resemble one another morphologically and are the only representatives of the genus with open, expanded leaves. They are, nevertheless, clearly distinct anatomically, particularly in the structure of the leaf blade as viewed in transverse section. The anatomy of M. cincta is noteworthy in the possession of additional vascular bundles located immediately below the first order vascular bundles. This vertical arrangement of bundles at differing levels is a unique feature of M. cincta and possibly indicates a need for taxonomic adjustment.