Montana Field Guide

Plants: Acrocarpous, growing in open clumps of upright shoots, green or green with yellow tones distally, brown proximally (Lawton 1971). Stems to 21 mm tall, the branching simple or sparse, possessing a central strand (FNA 2007); rhizoids brown, tangled into mats (Lawton 1971), and papillose (FNA 2007).

Leaves: Laxly spaced (FNA 2007) or sometimes overlapping a little, more distant below than above, the ends recurved when dry (Lawton 1971), typically broadest just below mid-leaf, lance-shaped (FNA 2007) to egg-shaped or somewhat oblong (Lawton 1971), tapering to an obtuse or nearly obtuse leaf tip, occasionally apiculate, 0.7-2 mm in length and to 0.7 mm in width, to 20 pairs, 2-ranked, enveloping the stem closely; vaginant laminae 1/2 the length of the leaf or somewhat longer, about equal to each other in length (FNA 2007), and broader than the apical lamina (Lawton 1971); dorsal lamina ending at or occasionally before the leaf base; margins scalloped to evenly and finely saw-toothed above, not bordered; costa ending just before to 14 cells before the leaf tip (FNA 2007), sometimes a little wavy distally (Crum & Anderson et al., 1981).

Leaf Cells: Lamina 1 cell-layer thick, the cells more-or-less 6-sided with firm walls (FNA 2007).

The similar F. adianthoides has a light-colored strip of marginal cells, and non-papillose rhizoids, unlike F. osmundioides. In addition, its sporophytes are in lower leaf axils rather than terminal at the stem apices (FNA 2007).

Shady, wet areas, acidic and nonacidic surfaces (Crum & Anderson et al., 1981), on stones near moving water, sometimes receiving the spray, moist soil and humus of seeps (FNA 2007), soil on top of stones, stone shelves on bluffs, logs (Lawton 1971), around tree bottoms, wetlands and meadows (FNA 2007).

Dioicous. Both male and female structures on somewhat long stems. Seta 1 to a perichaetium, to 2.5 mm in height (FNA 2007) or sometimes to 7 mm, terminal (Crum & Anderson et al., 1981). Capsule to 1 mm in length; stomata scarce below (FNA 2007); operculum about as long as the theca or longer; peristome single, the 16 teeth red and with papillae proximally (Lawton 1971) in longitudinal rows, and striations above (Crum & Anderson et al., 1981). Calyptra cone-shaped, 1.5 mm length (FNA 2007).