Montana Field Guide

Plants: Acrocarpous, growing in uncrowded clumps of erect shoots, deep green. Stems 2-10 cm in height, borne from short, subterranean rhizomes (FNA 2007).

Leaves: Somewhat twisted, curved and bent when dry, spreading close to 90 degrees with the leaf apex turned back and down when damp, 5-10 mm in length, the short sheathing base somewhat yellow with transparent, smooth margins, narrowing to the divergent blade with little joint tissue present where the two meet; blade slender and lance-shaped; margins with sharp teeth, sometimes fine, along the blade almost to the sheath; costa shortly extending beyond the apex (FNA 2007).

Leaf Cells: Marginal lamina 5-12 cells in width, bent up and inward somewhat (“holding in” the lamellae), the marginal teeth of the blade each consisting of 1 long cell (FNA 2007); lamellae 18-50, green, nearly completely obscuring the ventral leaf surface from shoulder to leaf tip (Crum & Anderson et al., 1981), from a side-view appearing like a wall of cells that are smooth to finely toothed along the top and 3-7 cells in height, the topmost (marginal) lamellar cell in X-section somewhat egg-shaped to oblong, more often taller than broad; sheath cells quadrangular, short; costa in X-section with large guide cells and a dorsal stereid band (FNA 2007).

Damp humus and soil in evergreen forest (Crum & Anderson et al., 1981), peaty bogs (from acidic to basic), tundra (FNA 2007); in alpine and subalpine habitats (Elliott & Pipp, 2016).

Dioicous. Perichaetial bracts a little larger and with a dentate awn but otherwise resembling stem leaves. Seta single, 4-6 cm in height, yellow above, russet below. Capsule ochre, 3-5 mm in length, typically with 5 or 6 angles (FNA 2007), the theca 3-4.5 mm in length (Lawton 1971), wider than the neck; peristome with about 50 teeth of varying profiles and sizes. Calyptra sheltering the upper part of the capsule, draping like a hood and covered with matted hairs (polytrichoid) (FNA 2007).