Montana Field Guide

Plants: Acrocarpous (Vitt 1988). Growing in crowded clumps of erect shoots (FNA 2014), typically a waxy green (Lawton 1971), occasionally noticeably blue (Crum & Anderson et al. 1981). Stems unbranched or forked once, 5-sided in X-section, brown (FNA 2014), 5-30 mm; possessing a central strand (Lawton 1971) and a hyalodermis; rhizoids forming a tangled mat below, smooth (FNA 2014).

Leaves: Rigid, upright and overlapping when dry or wet, 5-ranked, slender and lance-shaped, narrowing to form a short acumen or seldom bluntly tipped, 1-1.5 mm in length, sharply creased longitudinally in the middle; margins rolled back and under in the top half; finely saw-toothed; costa extending to or beyond the apex (occasionally not reaching it in lower leaves), the dorsal side mammillose (FNA 2014).

Leaf Cells: Alar cells not distinct; basal laminal cells quadrangular, fine-walled and swollen when wet; upper laminal cells quadrangular or short and diamond-shaped, thick-walled, smooth or with mammillae at the upper end of the cell dorsally and ventrally (FNA 2014).

Fruit ripens in summer (FNA 2014).

C. tetragonum has a distinctive appearance with its glaucous, upright, 5-ranked leaves and the exostome teeth fused distally to form a cone (FNA 2014).

Moist soil and rock, thin soil on rocky shelves, and areas with snow thawing late. Elevation to 7220 feet (FNA 2014).

Dioicous (Crum & Anderson et al. 1981). Perigonia bud-like or cup-shaped, intermingling with somewhat club-shaped, partitioned hairs; perichaetial bracts with a subula, bigger than the stem leaves. Seta 8-25 mm tall, red with yellow tones to brown. Capsule 2-2.5 mm in length (FNA 2014), widely ovoid and short, green or pink when immature, becoming brown and ribbed when dry (Lawton 1971); beak thick and tilted on the operculum (FNA 2014); exostome sections dark brown with a slender yellow edges (Crum & Anderson et al. 1981), perforated, joined at the tip to form a cone (FNA 2014).