Vegetative Proliferation of Floral Spikelets in British Grasses

Abstract

Proliferation of spikelets in grasses other than those races which are habitually viviparous is reviewed, and the factors inducing proliferation experimentally in Cynosurus cristatus and other species are discussed. It is concluded that the evidence favours the hypothesis that in the viviparous races a considerably greater minimal concentration of the putative flowering hormone is required for flower induction than for culm initiation, whereas in the seminiferous races this difference is not so great. In the viviparous races, the threshold for flower initiation is rarely exceeded so that perfect flowers appear only occasionally, whilst in the normally seminiferous races, the conditions arise only rarely where an amount of hormone is produced sufficient to initiate culms but insufficient to promote flowering.