Anatomical study of developmental stages of the sporophyte of living Odontoschisma prostratum (Sw.) Trev. revealed that the conspicuous swelling of the female branch during sporophyte development is correlated with a remarkably strong growth of the sporophyte foot. Thus, the enlargement of the female branch must not be looked upon as a “perigynium precursor.” The anatomy of the seta supplies new evidence for a close taxonomic relationship between Odontoschisma Dum. and Cladopodiella Buch.