Bot. Zeit. 4:324. 2. 1846.
Andreaea crassinervia var. obtusifolia Berggr., K. Svensk. Vet. Ak. Handl. 13(8): 40. 1875. -- Andreaea blyttii var. obtusifolia (Berggr.) Sharp in Grout, Moss Fl. N. Am. 1: 3. 1936.
Plants mostly in scattered tufts, to 10 mm high, sparingly branched, red-brown in younger portions but black in older portions. Stems dark red to black even in young material. Leaves, when dry, loosely appressed when dry, erect spreading from a somewhat sheathing base when moist. Leaves to 1 mm long, 4–5: 1, elliptic and concave at base but abruptly subulate from about the leaf middle to the blunt or acute apex, concave below, usually falcate. Median cells smooth throughout, arranged in regular rows, to 8 µm wide, isodiametric to transversely elongate with rounded lumens due to trigonous thickenings, incrassate with lumen/wall ratio about 1: 1. Marginal cells of leaf base irregularly rectangular, to 8 µm wide. Cells of median leaf base quadrate, to 12 µm wide, with rather thin (lumen: wall ratio 4–6: 1) walls. Costa excurrent in a subula which comprises up to 1/2 of leaf length, round in cross-section in subula but flattened and less conspicuous near base. Costa cross-section (at junction between subulate limb and concave base) formed of 3 layers of homogeneous cells with large lumens and thick walls. Margins ascending and entire throughout, not at all decurrent. Stem nearly homogeneous, of thick-walled cells without a central strand. Axillary hairs to 30 µm long, 2-celled, not offset, one isodiametric and concolorous, the other elongate and clavate, very thick-walled with lumen wall ratio about 1: 1. Gemmae never present.
Plant autoicous, perigonia on separate branches quite distant from the perichaetia. Perichaetial leaves much larger and elliptic ovate with costa abruptly excurrent in a short mucro, to 1.2 mm long, loosely sheathing the base of the pseudopodium. Pseudopodia to 1 mm long, straight. Capsule dark brown except for a pale apex, elliptic, 2: 1, to 0.8 mm long before dehiscence, opening by four longitudinal slits. Median exothecial cells to 25 µm wide, 3–4: 1, with thick but not pitted lateral walls and with thin transverse walls. Exothecial cells along lines of eventual capsule dehiscence more elongate and narrow in 1–2 irregular rows. Exothecial cells at capsule apex isodiametric and thick walled, somewhat smaller than median cells. Stomates absent. Spores to 50 µm, smooth, with trilete mark.
|Illustrations||Malcolm et al. 2009 p. 28; Murray 1987b.|
|Bioregions||CaR, CW, NW, SN.|
|Vouchers||Calaveras Co.: North Fork Mokelumne River west of Moore Creek, Stanislaus National Forest, Shevock 21742 (determined by Murray); Lake Co.: Boggs Mountain State Forest, Showers 1810 (SFSU) and Cobb Mountain, Toren & Dearing 7114 (CAS) [determined by Murray]; Madera Co.: above Whiskey Creek Falls, Sierra National Forest, Shevock, Norris, & Beyer 20237; Marin Co.: East Peak, Mt. Tamalpais State Park, Robertson 1728 (UC); Mariposa Co.: Highway 41 below Wawona Tunnel, Yosemite National Park, Shevock & Norris 20178; Shasta Co.: Castle Lake at Castle Lake Creek southwest of Mt. Shasta City, Shasta-Trinity National Forest, Norris & Hillyard 103852; Siskiyou Co.: McCloud River, 5 miles east of McCloud, Shasta-Trinity National Forest, Norris & Hillyard 103898; Tehama Co.: Highway 36 at milespost 96, Norris 55953; Tulare Co.: Lloyd Meadows Basin, Sequoia National Forest, Shevock 14259 (confirmed by Murray).|