Dicranum tauricum

Plants in dense tufts, light green to yellowish green, glossy. Stems 0.5–3 cm, tomentose below with whitish or reddish-brown rhizoids. Leaves straight, erect-spreading, little changed when dry, smooth, 4–6 × 0.2–0.4 mm, most of the leaf tips deciduous and absent, lanceolate, concave proximally, tubulose distally, apex acute; margins entire or serrulate at apex; laminae 1-stratose or with 2-stratose regions near apex; costa long-excurrent, 1/6–1/4 the width of the leaves at base, abaxial ridges absent; leaf cells smooth, with a row of guide cells, no stereid bands, 1 or 2 rows of cells above and below guide cells with slightly thickened walls and large lumens, the adaxial and abaxial epidermal layers of cells not differentiated; cell-walls between lamina cells not bulging; alar cells 1-stratose, differentiated, not extending to costa; proximal laminal cells rectangular to linear, with a few pits, (46–) 60–105 (–120) × (4–) 6–16 (–22) µm; distal laminal cells quadrate, rounded or short-rectangular, not pitted, (12–) 17–25 (–32) × (8–) 10–11 (–12) µm. Sexual condition dioicous; male plants as large as females; interior perichaetial leaves gradually narrowed to a subulate apex, convolute-sheathing. Seta 1.5–2.5 cm, solitary, yellow to light-brown. Capsule 1.4–2.5 mm, straight and erect, smooth, often irregularly wrinkled when dry, yellow to light-brown; operculum 1–1.8 mm. Spores 10–18 µm.

Phenology: Capsules mature in summer.
Habitat: Frequently on rotten logs, stumps, or tree bases in woodlands, sometimes on humus or humus over rock
Elevation: 150-2200 m

Alta., B.C., N.W.T., Sask., Alaska, Calif., Colo., Idaho, Mont., Nebr., Oreg., S.Dak., Utah, Wash., Wyo., Europe

Discussion

Dicranum tauricum has been reported from Utah by S. Flowers (1973). It is a western North American species, occurring on trees and rotten wood. It is recognized as glossy plants with broken off leaf tips and straight, erect capsules. It can be confused with D. fragilifolium, which also has broken off leaf tips and whose range overlaps with D. tauricum. For distinctions see discussion under 21. D. fragilifolium.

Selected References

None.

Lower Taxa