干旱区生态环境知识资源中心

Two desert species occurring in the same canyon were found to have divergent capsule maturation and sport liberation patterns. In the rock-dwelling Grimmia orbicularis, post-meiotic operculate capsules persisted for 3 months and the fall of the operculum occurred over a span of 3 weeks. In the soil-dwelling Tortula inermis. post-meiotic operculate: capsules persisted for 11 months and the period of operculum detachment lasted up to 2 1/2 years, In G. orbicularis. the course of spore liberation within the same sporophyte cohort lasted approximately 6 months. whereas in T. inermis spores within the same sporophyte cohort were released over a period of 3 years. The inclined nature of the capsule, the shorter and broader capsule dimensions, and the occurrence of populations on steeply inclined rock surfaces account for the relatively rapid fall of opercula and spore liberation in Grimmia compared to Tortula.