Seed dispersal and germination in Romulea rosea (onion grass)

Abstract

The role of sheep in the dispersal of seed of Romulea rosea was examined. It was found that the grazing animals ingested large numbers of seeds, and that although germination of defaecated seed was not high, each sheep dispersed more than 500 viable seeds per day. Under laboratory conditions sheep varied greatly in the rate of passage of seed, but germinability was not greatly reduced, compared with the original sample. Germination of samples of seed was studied on a thermogradient plate. Relative to some other components of pasture, germination was slow, and it was also much more reduced by temperatures above 16.5°C. These features, and perennation through corms, assist Romulea rosea in persisting in areas of variable summer rainfall.