Montana Field Guide

Plants: Pleurocarpous (Vitt 1988). Growing in open clumps of semi-erect shoots or in mats, green with yellow tones, or brown (FNA 2014), frequently shiny (Lawton 1971). Stems upright or nearly so, or prostrate with the tip ascending to upright, to 7 cm in length, the prostrate stems freely branched and the upright ones pinnate; possessing a central strand (sometimes weakly formed) and a hyalodermis; rhizoids growing from stems, frequently branched (FNA 2014).

Leaves: Leaves spreading somewhat, or upright and overlapping near the ends of stems and branches, 1-1.3 mm in width (Lawton 1971), 1.8-2.2 mm in length, not pleated longitudinally (FNA 2014), broadest at the base, cupped (Lawton 1971), dimorphic, the stem leaves egg-shaped, wider and shorter than the lance-shaped, auriculate branch leaves; base extending down the stem; margins flat or curving up and inward; leaf tip rounded or with an abrupt tooth-like point (cuspidate) (FNA 2014), frequently hood-shaped (Lawton 1971).

Stem Cells: Exterior cortical cells in 3-4 tiers, the interior cortical cells much bigger, with fine walls; pseudoparaphyllia leaf-like (FNA 2014).

Leaf Cells: Alar cells swollen and distinctive, the area well-demarcated; supra-alar cells somewhat square; basal laminal cells with thick, porose walls (FNA 2014), shorter than the medial cells; medial laminal cells long (Lawton 1971), wavy and twisted (FNA 2014).

When growing in wetlands with high water tables or in moist lawns (as in the Pacific Northwest), the plants acquire a partially upright, pinnate habit. Where the water levels vary, they branch erratically (FNA 2014).

C. cuspidata has stems with flattened apices and leaves that are not curved and pointing toward the same side of the stem, unlike sometimes similar Scorpidium species, which overlap in their fen habitat (Vitt 1988.)

Lake edges, mixed with Carex, calcareous wetlands, channels along roads, lawns. (FNA 2014).

Dioicous. Seldom fruiting. Perichaetia and perigonia developing in leaf axils (FNA 2014). Seta 35-50 mm in height, smooth, somewhat red (Crum & Anderson et al. 1981). Capsule level, bowed (FNA 2014), the theca 3-4 mm in length, 1-1.5 mm in width (Lawton 1971); exostome dentitions with delicate ridges below and papillae above, bordered; endostome sections folded longitudinally, with openings, the cilia with crosswise ridges (FNA 2014).