Montana Field Guide

Plants: Acrocarpous. Scattered (Lawton 1971) or growing in loose tufts, green to yellow, not shiny. Stems 3-10 mm tall (Crum and Anderson 1981).

Leaves: Upright, a little contorted when dry, (1.5)2-3 mm in length (Crum and Anderson 1981), oblanceolate, spatulate (Lawton 1971), elliptic, the blade forming an apiculus or mucro; apex widely acute, sometimes rounded; margins flat above, curved back along the proximal 1/2 or 2/3, nearly smooth to small-toothed near the bottom of the acumen; border in the lower 2/3 (sometimes almost reaching the apex) consisting of yellowish, narrow, somewhat elongate cells in 2 layers (Crum and Anderson 1981) in 2-3 rows and with thicker walls (FNA 2007); costa typically ending in the acumen, but sometimes extending slightly beyond it (Crum and Anderson 1981).

Leaf Cells: Distal leaf cells 4-6-sided, 1-2 times longer than wide, sometimes lightly papillose (FNA 2007), the papillae typically C-shaped (Crum and Anderson 1981); cells generally smooth with the walls a little thickened (Lawton 1971).

Capsules ripen in summer (FNA 2007).

T. cernua has leaf cells that are mostly smooth and a peristome that is not spiraled. This contrasts to the similar T. laureri that has papillose leaf cells (strongly 2-pronged in the distal cells) and a twisted (weakly up to a full turn) peristome (FNA 2007).

Soil and limestone (Elliott 2016), from low to medium elevations (FNA 2007).

Autoicous. Setae russet (Flowers 1973) ca 0.6-1.7 cm tall and frequently slightly wavy or twisted (Crum and Anderson 1981). Capsules are ovoid- or rounded-cylindric, short, somewhat drooping or sometimes almost level (FNA 2007), longitudinally ridged when dry and empty (Crum and Anderson 1981); theca 1-1.8 mm in length; the 16 teeth forked 2-3 times nearly to the base (FNA 2007); operculum 0.4-0.6 mm in length, cone- to somewhat beak-shaped, the cells in rows that slant a little (Crum and Anderson 1981).