Montana Field Guide

Plants: Pleurocarpous. Green, sometimes tinged with gold above, brown below (Lawton 1971), shiny. Stems creeping, to 12 cm in length; central strand wanting; axillary hairs with lowest cell brownish and square, and 3-4 longer, hyaline upper cells; rhizoids growing from the back of leaf attachments (FNA 2014).

Leaves: Somewhat obscurely arranged in 3 vertical rows, strongly keeled, curved sickle-like to coiled, particularly at the distal ends of the stems and branches, lance-shaped and very thin, narrowing to a long, thread-like and acuminate leaf tip, the leaf length 4-5 mm, the width of centrally-placed stem leaves 0.4-0.8 mm; margins smooth and flat; costa extending well beyond the apex (FNA 2014).

Leaf Cells: Medial laminal cells very thin; alar cells square or quadrangular, only slightly larger than adjacent cells, if at all (FNA 2014).

The leaves may lie folded in half on a microscope slide, showing only half their width (FNA 2014).

Tree bark on branches and trunks (alder, cottonwood, maple, oak), roots, edges of ponds, swamps, lacustrine deposition areas, seldom on stone; frequently inundated, semi-aquatic. Elevation: 0-3610 feet (FNA 2014).

Perichaetial bracts to 6 mm in length. Perigonia bud-like. Seta 5-11 mm tall (Crum & Anderson et al. 1981), sheathed by the perichaetial bracts; capsule 1-3 mm in length, carried just beyond to partially hidden in the perichaetial leaves; operculum cone-shaped, 1-1.5 mm in length; peristome double; exostome teeth 16, sharply papillate; endostome ochre to somewhat reddish, the divisions unified by crosswise bars throughout (forming a perfect cone-shaped trellis) and longer than the exostome teeth. Calyptra 3-5 mm in length, concealing the capsule and frequently gripping the seta when young (FNA 2014).