Chromosome Numbers of a few South African Grasses

The chromosome numbers of 47 species belonging to 29 genera have been counted. Of these 38 species and 10 genera were previously unknown cytologically. The following genera have been investigated for the first time cytologically: Enneapogon (n=12); Pogonarthria (n=10); Triraphis (n=10); Acroceras (n=9); Rhynchelytrum (n=9); Schizachyrium (n=10); Urochloa (n=10); Bothriochloa (n=10); Dichanthium (n=10); and Hemarthria (n=10). The genus Aristida is characterized by two basic chromosome numbers, n=11 and n=12. Two chromosome races have been observed in Hyparrhenia hirta, 30 chromosome diploids and 45 chromosome tetraploids. H. aucta with 2n=20 seems to be characterized by a basic chromosome number of n=10.