Montana Field Guide

Plants: Acrocarpous (Vitt 1988), growing in thick, crowded clumps of upright shoots and developing from a subterranean rhizome, green, or green with a whitish cast, eventually becoming deep brown (FNA 2007). Stems occasionally branched (Lawton 1971), mostly 6-12 cm tall, obscured with an interwoven, woolly, pale brown to white covering of rhizoids (FNA 2007) which are noticeable amongst the leaves (Lawton 1971).

Leaves: Overlapping and pressed flat against or loosely near to the stem when dry, spreading a little when wet (FNA 2007), 3-5 mm in length (Lawton 1971), consisting of a blade (limb) above a clasping sheath (FNA 2007); sheath somewhat yellow (Lawton 1971), suddenly constricted at the sheath/blade juncture, the sheath margins transparent; blade plane and slender, lance-shaped and narrowing to form an acumen; blade margins transparent, smooth or shallowly and finely scalloped, curved inward abruptly and enveloping the lamellae (rib-like flaps or walls of cells running longitudinally along the ventral blade surface), the margins overlapping each other near the leaf tip (FNA 2007); lamellae 25-30, seldom to 35 (Lawton 1971), green, nearly covering the blade (Crum and Anderson et al. 1981); costa extending slightly beyond the leaf tip, forming a short brownish awn, with teeth on the outside of the leaf near the apex (FNA 2007) and on the awn (Lawton 1971).

Leaf Cells: Lamellae 5-8 cells tall, looking shallowly scalloped in profile, in X-section the topmost (“marginal” or “terminal”) cells of the lamellae pear-shaped and thick-walled, with a bulge on top, the cells of the lamella closest to either leaf margin egg-shaped and not thickened on top; margin of the lamina of 1 cell-layer and 6-7 cells in width, the cells lengthened crosswise, and slightly slanted relative to the margins, hyaline; sheath cells oblong and somewhat long, wider further in from the margin (FNA 2007).

The similar Polytrichum juniperinum resides in mineral soil rather than organic soil as with Polytrichum strictum, and has brown woolly rhizoids restricted to the base rather than whitish tomentum all over the stem (Vitt 1988; Lawton 1971).

Organic soil and peat in wetlands and alpine tundra (Elliott and Pipp 2016). Occurring from low elevations to about 7870 feet (Lawton 1971).

Polytrichum strictum frequently grows individually on hillocks of Sphagnum, signaling the driest spots of the hillock (Vitt 1988).

Dioicous. Periogonial bracts wide and overlapping, forming noticeable rosettes. Perichaetial bracts slenderly awned. Seta russet or somewhat yellow, 20-40 mm tall. Capsule nearly cubic or slightly lengthened with the 4 angles sharp, 2-3 mm in length, just shy of vertical, becoming level when mature; peristome with 64 teeth. Calyptra pale brown to a soiled white, thickly covered with intertwined hairs, encompassing the entire capsule (FNA 2007).