The relation between the occurrence of polysety and the number of archegonia in female inflorescences of Dicranum majus and D. scoparium.

Abstract

Inflorescences of Dicranum scoparium contain 7–9 archegonia on average compared with 13–15 in D. majus. In D. majus polysety was observed in 55% of fertile shoots. There is no evidence that the occurrence of polysety in D. majus is associated with any increase in the number of archegonia. This was interpreted to show that all inflorescences contained four or five ripe archegonia at the time of fertilization. Since monosetous inflorescences were more common than polysetous ones, it was concluded that the supply of antherozoids was not saturating for fertilization. In D. scoparium polysety was observed in only 5% of fertile shoots.