The reproductive biology of three sympatric species of Dicranoloma Ren. was investigated: D. billardierei (Brid. ex anon) Paris, D. menziesii (Taylor) Renauld, and D. platycaulon Dixon. The developmental stages of gametangia and sporophytes were identified for each species and a maturity index value assigned. Although archegonia were initiated after antheridia, archegonia matured within two months while antheridia took five to six months to reach maturity. Antheridia were initiated during winter and archegonia in spring in D. menziesii and D. platycaulon. In contrast, antheridia were initiated during late spring-summer and archegonia in autumn in D. billardierei. Fertilization occurred in late summer in D. menziesii, mid autumn in D. platycaulon, and early winter in D. billardierei. An overlap in sporophyte generations occurred in D. billardierei and D. platycaulon. Maturation of the sporophyte took 18–24 months in these species, whereas sporophytes of D. menziesii matured within 12 months.