Mniaceae. Genus Cyrtomnium

1. Shoots complanate-foliate; leaves apiculate, strongly narrowed to the base, not decurrent; costae occupying more than 3/4 of leaf base; marginal leaf borders with 24 rows of narrow cells with strongly oblique end walls 1. C. hymenophylloides

This species is conspicous and can be recognized by its complanate-foliate, pale- or glaucous-green leaves that are so strongly narrowed to the base that they appear to be attached to stem by only the costa. Cyrtomnium hymenophylloides usually grows in rock crevices or on sheltered cliff surfaces; it occurs in continental areas with calcareous bedrocks and grows abundantly in mountain tundra regions, often in association with Orthothecium chryseum.

­ Shoots terete-foliate; leaves acute, moderately narrowed to the base, decurrent; costae occupying less than 1/3 of leaf base; marginal leaf borders with 12(3) rows of relatively broad cells with moderately oblique end walls 2. C. hymenophyllum

Cyrtomnium hymenophyllum is similar to C. hymenophylloides in having glaucous colored plants. Furthermore, fertile (male) plants of C. hymenophylloides are sometimes terete-foliate and this may cause problems in separating the two species. But, the presence of some or many complanate-foliate plants in large populations of C. hymenophylloides is always apparent. The presence of broadly decurrent leaves allows for the reliable recognition of C. hymenophyllum in the field. Cyrtomnium hymenophyllum has a mainly Arctic distribution with scattered localities in other cold regions of Russia, mainly within the permafrost zone.