Montana Field Guide

Plants: Acrocarpous (Vitt 1988). Growing in somewhat open to crowded tufts (Flowers 1973), frequently creating large carpets, somewhat reddish-green (like olives) or with black tones. Stems 3-20 mm in length (FNA 2007), occasionally forked; central strand absent (Lawton 1971).

Leaves: Sometimes spiraled around the stem a little, appressed, overlapping, and folded in toward the center when dry, upright and spreading somewhat when wet, 1-2.5 mm in length, 0.6-1.2 mm in width, egg- to spatula-shaped (FNA 2007), cupped, particularly near the apex; margins unbordered (Lawton 1971), smooth, tightly rolled out and downward throughout; apex a short acumen or acute; costa extending beyond the leaf tip to form an awn; awn black or brown (no red), transparent proximally, saw-toothed, with the many, sometimes stellate, papillae occasionally creating a frosted look (FNA 2007).

Leaf Cells: Costa in X-section with 2-4 guide cells (Lawton 1971) and sub-stereid cells; lamina with 2 or more cell layers, sometimes sprinkled with 1-layered regions (FNA 2007), particular below (Lawton 1971), the cells not swollen; upper cells somewhat swollen, round, square, or with sides varying, covered with low and numerous papillae, the papillae 4-6 per cell (FNA 2007), simple or lobed (Lawton 1971); basal cells large, transparent, smooth, and fine-walled, well-demarcated, more slender at the margins (FNA 2007); margins frequently of 2 cell layers their whole length (Lawton 1971).

Unlike Tortula ruralis with its sometimes rosy costal base, T. caninervis has no traces of red in its costa (FNA 2007).

Soil in deserts or semiarid grasslands. Montane and higher elevations (FNA 2007).

Dioicous. Seta 6-14 mm tall (Lawton 1971), brown. Capsule 1.5-3.2 mm in length, red, sometimes bowed a little, with a clear neck; peristome with 32 reddish and papillose thread-like divisions spiraled together (FNA 2007) in 1.5 or more revolutions (Flowers 1973).

Specialized vegetative reproduction lacking (FNA 2007).