Montana Field Guide

Plants: Pleurocarpous (Vitt 1988). Growing in open to crowded, erect clumps (FNA 2014) or mats (Lawton 1971), dark green, ochre with red tinges, occasionally various leaves of a plant dotted with rust-colored spots. Stems prostrate, straight or a little bowed, appearing with the leaves circular in X-section, up to 5 cm in length; possessing a central strand. Branches up to 6 mm in length (FNA 2014).

Stem Leaves: Spreading somewhat when moist, flat against the stem and somewhat to considerably overlapping when dry (Lawton 1971), egg-shaped, sometimes tending toward lance-shaped, 1.4-2 mm in length, 0.4-1 mm in width, not pleated (FNA 2014) or minutely so, deeply cupped (Lawton 1971); margins finely saw-toothed, flat or curved back and downward proximally; base extending along the stem a little; apex with a short acumen; costa 1/3 to 2/3 the length of the leaf; widest near the base, quickly becoming more slender in the lower 1/3 of the leaf, the dorsal spine lacking or minute (FNA 2014).

Branch Leaves: Smaller and more slender than the stem leaves; margins less finely saw-toothed (FNA 2014).

Leaf Cells: Alar cells nearly square (Lawton 1971) with medium-thick walls, the cells next to the costa about the same size or a little smaller, the alar area opaque (FNA 2014); basal cells wider and not as long as the median cells (Lawton 1971), arranged in 3-7 tiers crosswise to the base, the area opaque (FNA 2014); upper cells long and narrow (Crum and Anderson et al. 1981).

Northern plants growing on rock in mostly wet conditions occasionally have very curved leaf apices whereas southern plants in drier habitats are straight and slenderer. The rusty-red spots and the opaque cells extending across the bottom are distinctive. The occasional opacity of the leaf corners of Sciuro-hypnum oedipodium does not extend across the base (FNA 2014).

Sciuro-hypnum populeum also has short, rather even cells across the base; however, the costa is percurrent or nearly so (over 4/5 the leaf length). That of S. plumosum is shorter (FNA 2014).

Bark on tree bases, shaded rocky bluffs and outcrops (FNA 2014), wet rock in streams and on cliffs (Elliott 2016). Elevation: 0-10,170 feet (FNA 2014).

Autoicous. Perichaetial leaves enveloping the stem proximally, the apices spreading (Lawton 1971). Seta 1.2-2.4 cm tall, red, papillae-roughened (occasionally faintly so). Capsule 1.3-2 mm in length, ascending somewhat, rounded a little more on the upper side than the bottom, red (FNA 2014) or deep brown; cilia knobby or with crosswise projections (Lawton 1971).