Montana Field Guide

Plants: Acrocarpous (Vitt 1988). Shoots growing upright and in clumps or scattered (Lawton 1971), not shiny (Crum & Anderson et al. 1981), green above, with shades of brown below (FNA 2007). Stems 2-20 mm tall (Flowers 1973), sometimes forked, possessing a central strand; axillary hairs to 8 cells long, the distal cells with thinner walls (FNA 2007).

Leaves: Upright against the stem and infolded when dry, spreading slightly to broadly when wet, egg-shaped (FNA 2007) to spathulate (Flowers 1973), with the apex nearly obtuse and sometimes rounded (FNA 2007), 1.5-3 mm in length, 0.6-0.8 mm in width (Lawton 1971); margins curved back and down in the middle part of the leaf, wavy near the apex (FNA 2007) and smooth proximally; costa narrowing distally, extending beyond the leaf tip and forming a mucro or hair-point in the distal leaves, frequently subpercurrent in the proximal leaves with the laminal cells then sometimes creating the mucro (Flowers 1973), or some leaves muticous (FNA 2007).

Leaf Cells: Basal cells quadrangular with thin, transparent walls; upper laminal cells 1:1, 6-sided, thickly covered with papillae, the papillae sometimes 2-lobed; leaf edges unbordered or faintly bordered with diamond-shaped cells, the cells smaller and with fewer papillae than adjacent cells; mucro of long, clear cells; costa in X-section convex on the ventral surface, with a ventral epidermis (FNA 2007), sub-ventral guide cells (usually in 1 row) (Flowers 1973), hydroid strand, a strong semi-circular dorsal stereid band, and a dorsal epidermis (FNA 2007) of cells somewhat larger than the adjacent stereids (Flowers 1973).

Phenology: Fruit ripens in summer (FNA 2007).

Laminal cells thickly covered with 2-lobed papillae, and the wavy apical margin leading to the usually long mucro (some leaves lacking a mucro) with long, clear cells are characteristic (FNA 2007).

Soil, sometimes calcareous (FNA 2007), sometimes on soil in stone fissures (Crum & Anderson et al. 1981); montane (Lawton 1971) to alpine and in tundra (FNA 2007).

Autoicous (FNA 2007), but plants frequently only producing either male or female gametangia (Lawton 1971). Seta 9-19 mm tall. Capsule brownish, upright, scarcely curved, carried fully beyond the perichaetial leaves; theca 1.5-2.8 mm in length (FNA 2007); operculum with a tilted beak (Crum & Anderson et al. 1981); peristome sections 16, seldom spiraled, split nearly the full length or just below, frequently united in 2’s or larger groups. Calyptra hood-like (FNA 2007).