AbstractInflorescences ofDicranum scopariumcontain 7–9 archegonia on average compared with 13–15 inD. majus. InD. majuspolysety was observed in 55% of fertile shoots. There is no evidence that the occurrence of polysety inD. majusis 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. InD. scopariumpolysety was observed in only 5% of fertile shoots.