THE SOMATIC CHROMOSOME COMPLEMENT OF HABRANTHUS ROBUSTUS

MEMBERS OF the Zephyrantheae have received but slight cytological attention. The small number and favorable size of the chromosomes of Habranthus robustus Herbert, of this tribe, were noted in the course of some routine chromosome counts. Since the cytological evidence also lends support to recent taxonomic contentions, it seems desirable to report the facts at hand. The chromosome descriptions reported here deal with external morphology and are based on studies of root-tip cells in smear preparations. The preparations were made after Warmke's (1935) method and Brown's (1937) modification of it. The chromatin so nearly fills the cell in division that it is necessary to flatten the cells, often to the bursting point, in order