Abstract
Pollen samples were taken monthy, May through October, from 22 clones of Andropogon saccharoides var. torreyanus, grown under two treatments. The mean sample size for all collections was 35.3 µ and the extreme range was 31.4–38.1 µ. Analysis of variance indicated highly significant differences in pollen size between clones and between sampling dates. In a second analysis no significant difference was found between old plants and transplants. Over 18,000 pollen grains were measured in a comparative study of pollen size in nine Andropogon taxa. A consistent relationship was found between pollen size and chromosome number for three 2n=60 taxa, five 2n=120 taxa, and one 2n=180 taxon. The difference in pollen size between two 2n=120 chromosome taxa is interpreted as reflecting a difference in the pollen size of the three 2n=60 parent types from which they are assumed to have arisen.