Montana Field Guide

Plants: Acrocarpous (Vitt 1988). Brown with reddish tones, or black, with green ends. Stems mostly simple (Lawton 1971), 3-8(-13) cm, upright (FNA 2014).

Leaves: Brown or green, with reddish hues, becoming black with age, spreading when wet, contorted when dry, largely plane, widely elliptic or obovate, seldom circular, (2.5-)3.5-4.5(-6) mm; leaf base usually extending a short distance along stem or, infrequently, not at all; margins usually slightly revolute, seldom plane, 1-layered; apex usually broad or rounded, sometimes acute or forming a sharp apiculus or toothed cusp; the strong costa ranging from excurrent to seldom subpercurrent (FNA 2014).

Leaf Cells: Median laminal cells long with pitted walls (FNA 2014), larger near costa than near the margin (Lawton 1971), forming slanted rows; marginal cells differentiated, linear or narrowly- and short-rectangular, consisting of (2-)3-4 rows (FNA 2014), one-layered (Lawton 1971).

Capsules ripen in summer (FNA 2014).

Restricted to rich, calcareous fens and seeps (Elliott 2016). In rich fens, look for the rare Cinclidium stygium when Catoscopium nigritum or Calliergon trifarium are present. It may be found in calcareous seeps of the alpine with Paludella squarrosa (Vitt 1988).

Synoicous (FNA 2014). Seta 4-7 mm, flexuose, yellowish. Capsule yellow, 2-3 mm, broadly elliptic (FNA 2014), nodding and smooth cylindric (Vitt 1988); peristome teeth yellow with hues of green; upper parts of the endostome joined to form a dome (Lawton 1971).