Plants 1-4 cm. Stem central strand present. Leaves broadly oblong-ovate to narrowly ovate-lanceolate or ligulate from an ovate base, concave, margins plane or incurved, costa immersed; basal marginal cells hyaline or not; distal lamina 2-3-stratose. Gemmae absent. Sexual condition dioicous. Seta straight or sigmoid, centrally attached to capsule. Capsule exserted (emergent in G. nevadensis), smooth; stomata present or absent, small, at base of capsule. Calyptra mitrate to cucullate, covering operculum.

Species 15 (7 in the flora): North America, Mexico, Central America, South America, Eurasia, Africa, Indian Ocean Islands, Australia.

Members of subg. Litoneuron are recognized by their thick, concave leaves with plane margins and costa not projecting prominently from the lamina. The stems have well-developed central strands. They are dioicous, and capsules are not common, but if present they are usually long-exserted on a straight or rarely only slightly sigmoid seta. The annulus is typically large and prominent but is absent in Grimmia hamulosa. Members of the subgenus have habitat preferences ranging broadly from dry exposed rocks to stream banks and cliff faces along lake shores. They are found on acidic to basic rocks ranging from near sea level up to the alpine zone.

Lower Taxa

• Grimmia hamulosa Lesquereux
• Grimmia laevigata (Bridel) Bridel
• Grimmia nevadensis Greven
• Grimmia olneyi Sullivant
• Grimmia ovalis (Hedwig) Lindberg
• Grimmia serrana J. Muñoz
• Grimmia unicolor Hooker