Dicranum fuscescens
Muscol. Hibern. Spic., 60, plate 5, fig. 1. 1804,.
Plants light green to dark brownish green, dull, in loose tufts. Stems 1–6 (–18) cm, tomentose to scarcely tomentose with white or reddish-brown rhizoids. Leaves falcate-secund, often strongly so, sometimes somewhat sparse, distal leaves curled, proximal leaves with flexuose apices, slightly to strongly curled and crisped when dry, smooth, (3–) 4–7 (–10) × 0.6–1 mm, concave below, keeled above, from a lanceolate base to a gradually narrowed, fine, keeled subula; margins entire proximally, serrulate to strongly serrate in the distal half, sometimes nearly entire throughout; laminae 1-stratose and usually 2-stratose above on one or both margins, rarely some 2-stratose regions near costa; costa excurrent, 1/6–1/4 the width of the leaves at base, strong, terete, papillose to spinose distally on abaxial surface, occasionally almost smooth, sometimes extending to costa, abaxial ridges absent, with a row of guide cells, 2 well-developed stereid bands extending to distal part of leaf, adaxial epidermal layer of cells not differentiated, abaxial epidermal layer differentiated; cell-walls between lamina cells slightly bulging; leaf cells smooth to slightly papillose below on abaxial surface, papillose to spinose prorate above on abaxial surface; alar cells 2-stratose, strongly differentiated, sometimes extending to costa; proximal laminal cells elongate, pitted, (19–) 43–62 (–93) × (2–) 6–8 (–12) µm; distal laminal cells irregularly rounded, elliptic, short-rectangular to quadrate, not pitted, (7–) 9–23 (–36) × (4–) 8–12 (–14) µm. Sexual condition dioicous; male plants as large as females, growing intermixed, or in separate patches; interior perichaetial leaves abruptly short-acuminate, convolute-sheathing. Seta 1–3.5 cm, solitary, yellow, reddish yellow or brown. Capsule 1–3 mm, arcuate, inclined to horizontal, strumose, strongly furrowed when dry, somewhat contracted below mouth, dark-brown to reddish-brown; operculum 1–2 mm. Spores 14–24 µm.
Distribution
North America, Europe, Asia
Discussion
Varieties ca. 7 (2 in the flora).
l. Plants small, stems 1–6(–10) cm, usually densely foliate; leaf margins serrulate to strongly serrate in distal half; costa papillose to spinose distally on abaxial surface; distal laminal cells short-rectangular to quadrate, mostly 18–23 µm long; seta mostly shorter than 2.5 cm
15a. Dicranum fuscescens var. fuscescens
Selected References
None.
Key
| 1 | Plants small, stems 1-6(-10) cm, usually densely foliate; leaf margins serrulate to strongly serrate in distal half; costa papillose to spinose distally on abaxial surface; distal laminal cells short-rectangular to quadrate, mostly 18-23 µm long; seta mostly shorter than 2.5 cm | Dicranum fuscescens var. fuscescens |
| 1 | Plants large, stems 8-18 cm, sparsely foliate; leaf margins nearly entire; costa almost smooth on abaxial surface; distal laminal cells irregularly rounded, elliptic or short- rectangular, mostly 9-19 µm long; seta usually 2.5 cm long or more | Dicranum fuscescens var. flexicaule |