Chromosome Numbers of a few South African Grasses

Abstract

The chromosome numbers of 47 species belonging to 29 genera have been counted. 38 species and 10 genera were previously unknown. The following genera have been investigated for the first time cytologically: Enneapogon (n=12); Pogonarthria (n = 10); Triraphis (n = 10); Acroceras (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. In Hyparrhenia hirta 30-chromosome diploid and 45-chromosome tetraploid races have been observed.