Montana Field Guide

Plants: Acrocarpous (Vitt 1988). Growing in open to crowded clumps of erect shoots, pale to deep green, occasionally shiny. Stems 2-10 cm tall; rhizoids pale to brown, forming woolly mats on the stem (FNA 2007).

Leaves: Shape quite variable, a little curved and twisted when dry, typically curved and pointing toward one side of the stem, seldom straight and upright, most often smooth but occasionally with crosswise waves, lance-shaped, cupped below, longitudinally ridged above, 4-15 mm in length, 0.8-1.8 mm in width; apex acute or broader; margins typically saw-toothed above, seldom finely so to subentire; costa ending just before to slightly beyond the apex, typically with 2-4 dentate crests on the dorsal side (FNA 2007) from about mid-leaf to the apex (Lawton 1971), although the crests are nearly vanished in some forms (FNA 2007).

Leaf Cells: Lamina 1 cell-layer thick, the cells smooth and the walls between the cells not protruding; upper laminal cells wavy and porose; lower laminal cells very thin and quadrangular, porose, longer than the upper cells; alar cells distinct, inflated, occasionally reaching the nerve, the alar area 2 cell-layers thick; costa in X-section with guide cells in 1 row, the ventral and dorsal stereid bands both narrow, the ventral superficial cells not distinct, the dorsal superficial cells interspersed with a few bigger cells that are part of the dentate dorsal crest, not reaching the apex (FNA 2007).

Fruit ripens in spring (FNA 2007).

The variable leaves are mostly lance-shaped with a long acumen, but occasionally are ovate-lanceolate with a short acumen. Plants in the far north and those in wetlands often develop leaves with superficial differences (FNA 2007).

D. scoparium plants that are sterile and big-leaved may resemble D. majus. The costal anatomy of the two species differs on several points, one concerning the guide cells (in 2 rows in D. majus instead of 1). Also, when fruit is present, D. majus presents 2-5 sporophytes in a perichaetium rather than the 1, or seldom 2, of D. scoparium (FNA 2007).

Humus overlying rock, soil, rotten wood, bottoms of trees in forests, occasionally wetlands. Elevation: 160-9510 feet (FNA 2007).

Dioicous or sometimes small males growing on female plant rhizoids. Inner perichaetial bracts enveloping the stem, suddenly narrowing to the long acumen. Seta single or seldom 2 in a perichaetium, ochre to russet, 20-40 mm tall. Capsule bowed, tilted to level, ochre to russet, smooth or finely longitudinally-ridged when dry, 2.5-4 mm in length; 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).