Montana Field Guide

Plants: Acrocarpous, growing in open clumps of upright shoots, green or green with yellow tones distally on the stem, brown proximally (Lawton 1971). Stems to 8.5 cm tall, usually forked, with a central strand; rhizoids smooth (FNA 2007) and tangled proximally (Lawton 1971).

Leaves: Laxly spaced or sometimes overlapping a little, the ends recurved when dry (Lawton 1971), somewhat wavy, lance-shaped or with the long sides nearly parallel, tapering to an acute or sometimes obtuse leaf tip, sometimes reaching 3.5 mm in length and 1.2 mm in width, to 60 pairs, 2-ranked, enveloping the stem closely; vaginant laminae 1/2 the length of the leaf or slightly longer; dorsal lamina not extending down the stem, ending at the leaf base; margins not bordered, scalloped to evenly and finely saw-toothed below, the teeth becoming irregular above; costa ending at or just before the leaf tip (FNA 2007), sometimes a little wavy distally (Crum & Anderson et al., 1981).

Leaf Cells: Lamina mostly 1 cell-layer thick, the dorsal and ventral laminae seldom with 2 layers in erratic patches, the cells square to 6-sided with firm walls; margins with 1-5 rows of cells lighter in color, more slender and thicker-walled than more interior cells, creating a weak marginal strip; cells of vaginant lamina a little larger (FNA 2007).

The similar F. osmundioides lacks the light-colored strip of marginal cells, has papillose rhizoids, and sporophytes terminal at the stem apices rather than in the lower leaf axils (FNA 2007).

In the spray of waterfalls (Crum & Anderson et al., 1981) or near moving water on moist soil generally, stones, and rotting wood (FNA 2007), humus, tree bark (Crum & Anderson et al., 1981), seeps and meadows (FNA 2007).

Possibly dioicous but perigonia unseen; perichaetia usually on short, lateral branches below. Seta 1 per perichaetium, to 25 mm in height (FNA 2007), lateral (Crum & Anderson et al., 1981). Capsule sloping upwards, somewhat bowed, to 1.5 mm in length; stomata scarce below (FNA 2007); operculum about as long as the theca; peristome single, the 16 teeth red and with papillae proximally (Lawton 1971). Calyptra draping hood-like, reaching to 2.5 mm (FNA 2007).