Montana Field Guide

Plants: Acrocarpous (Vitt 1988), growing in loose clumps or cushions of upright shoots (FNA 2014), darkly shaded (Vitt 1988) with a glaucous appearance. Stems sometimes reaching 25 mm in height (FNA 2014).

Leaves: Closely overlapping and pressed next to the stem, with the apex curved inward when dry, spreading, sometimes broadly, when damp, 2-2.7 mm in length, lance-shaped and tending toward oblong, narrowing to the obtuse or dull leaf tip; leaf edges smooth, curved back and down below, and bent more sharply back and downward above (FNA 2014).

Leaf Cells: Upper laminal cells chlorophyllous (Crum & Anderson et al., 1981), arranged in 1 layer, somewhat round and isodiametric, with 1-3 cone-shaped or 2-lobed papillae over each lumen; lower laminal cells short and quadrangular to square, with fine walls without knobs (FNA 2014).

Dry, siliceous and limestone boulders and bluff walls with full-sun exposure. Occurring at elevations from about 1640 to 9840 feet (FNA 2014).

This species is capable of growing in exceedingly xeric habitats(Vitt 1988).

Autoicous. Seta twisted, to 1.5 mm tall. Capsule 1.2 to nearly 2 mm in length, partially emerged (halfway or more) to exserted slightly beyond the perichaetial bracts, with 8 prominent ribs the whole capsule length (or seldom 16 ribs, with 8 shorter ribs alternating with the longer ones), contracted proximal to the opening when dry; stomata sunken and somewhat hidden by adjacent cells; exostome typically of 16 upright or spreading teeth, frequently disappearing with age, papillose, and with lines arranged longitudinally or in a network; endostome absent; prostome scarcely developed. Calyptra cone-shaped, sheltering the full length of the capsule, with papillose hairs (FNA 2014).