Montana Field Guide

Plants: Acrocarpous. Growing in uncrowded clumps of erect shoots, shiny or not, yellowish or deep green. Stems 1-6 cm tall; rhizoids pale or russet and thickly covering the stem with woolly matting (FNA 2007).

Leaves: Frequently curled or twisted when dry, smooth, strongly curved to the side to almost straight when moist, not wavy (Lawton 1971), lance-shaped and tube-shaped, narrowing to the acute leaf tip, 4-8 mm in length, 0.5-1 mm in width; margins saw-toothed distally, smooth below; costa extending beyond the apex, with papillae or teeth dorsally from mid-leaf to the apex, lacking dorsal crests (FNA 2007).

Leaf Cells: Lamina 1 cell-layer thick, the cells smooth or frequently bearing papillae in the upper leaf half, the walls between the cells only bulging a little or not at all; upper margins rarely with 2 cell-layers; upper laminal cells square, short and quadrangular, or sometimes oddly angled or angles smoothed, not porose; lower laminal cells quadrangular (FNA 2007) to very thin (Lawton 1971), porose or not; alar cells distinct, inflated, frequently reaching the costa, the alar region 2 cell-layers thick; costa in X-section usually with strong ventral and dorsal stereid bands below but missing from the upper 1/4 or so, and 1 guide cell row, the cells on top of and below the guide cells big and fine-walled (FNA 2007).

Fruit ripens in summer (FNA 2007).

Sometimes mistaken for D. fuscescens. D. fuscescens prefers lower elevations, usually below 2620 feet, rather than higher ones like D. pallidisetum (infrequently growing between 1640 and 2620 feet). D. fuscescens has leaves slowly tapering to a deeply folded, subulate apex rather than a tube-like distal portion, and stereid bands reaching the apex rather than than vanishing ca 1/3 of the leaf distance below the apex (FNA 2007). The stereid bands of the similar D. muehlenbeckii also reach the apical part of the leaf (Lawton 1971).

Diocious. Inner perichaetial bracts enveloping the stem, suddenly narrowing to the short acumen. Seta mostly single, occasionally paired, and seldom 3 in a perichaetium, yellow, seldom acquiring red or brown tones over time, 10-25 mm tall. Capsule bowed and tilted, constricted below the opening, deeply ridged when dry, yellow to ochre, seldom acquiring red or brown tones over time, 1.5-3.5 mm in length (FNA 2007); operculum similar in length to the theca (Lawton 1971); peristome of 16 teeth, separated ca halfway down into 2 lobes (seldom 3), russet, with papillae above. Calyptra hood-like, hairless, sheltering much of the capsule, falling away easily (FNA 2007).