STUDIES IN CYPERACEAE IN SOUTHERN AFRICA .30. ASPECTS OF THE RELATIONSHIP BETWEEN CYATHOCOMA AND COSTULARIA

The relationship between Costularia natalensis C.B. Clarke and the two endemic species Cyathocoma ecklonii Nees and C. hexandra (Nees) J. Br owning comb. nov., previously foreshadowed by a study of epidermal sil ica deposits, is substantiated by further evidence of morphological si milarity. Floret number and disposition in the spikelet is considered for these taxa, and fruit structure, including pericarp anatomy, is de scribed and illustrated. Costularia brevicaulis C.B. Clarke is contras ted with the other three. In several of its characteristics it resembl es the southern genus Oreobolus R. Br., particularly O. ambiguus Kuk. & Stern, however, differences from both Costularia and Oreobolus are s ufficient for it to be raised to independent generic ranking.