Montana Field Guide

Plants: Acrocarpous, growing in sometimes extensive, dense carpets or cushions, the wiry stems parting from each other easily with disturbance, olive green, green with brownish tones, sometimes extremely dark (FNA 2007), older leaves turning red with yellow tones (Bremer 1980). Stems 5-40 mm in height, usually under 20 mm, possessing a well-developed central strand (FNA 2007).

Leaves: Upright and typically overlapping when dry, 0.7-1.8 mm in length, lance-shaped or deltoid, either way with ovate tendencies, tapering to an acute apex, strongly longitudinally folded above along the mid-line, cupped below; leaf edges smooth, typically curved back and down; costa extending well beyond the leaf tip, forming an awn; awn typically extending back down the leaf edges a little, slightly bent or zigzagged, with tiny sharp teeth (FNA 2007).

Leaf Cells: Lamina largely 2 cell-layers thick above, but irregularly so; upper laminal cells short and oblong to square or egg-shaped, straight to slightly wavy, smooth; lower laminal cells square or wider than long, the longitudinal cell walls occasionally thinner than the crosswise walls; leaf edges of 1 or 2 cell-layers (FNA 2007).

Fruit ripens the last part of spring into the first part of summer (FNA 2007).

The dense carpets/cushions of wiry stems that part easily when disrupted is a distinguishing feature (FNA 2007).

Stones (FNA 2014), limestone and granite (Bremer 1980), in and along stone fissures; in the open or receiving dappled shade (FNA 2007). Mostly found in the Arctic; however, the plants grow in North America at high elevations in the Rocky Mountains (Bremer 1980). Occurring from lowlands to elevations of 14,760 feet (FNA 2007).

Dioicous. Sporophytes and male plants seldom produced (Bremer 1980). Capsule 0.6-1.1 mm in length, deep red or brownish, cup-shaped, rather short; peristome pale brown and covered with papillae and openings. Calyptra not completely shielding the capsule (FNA 2007).