Blindia acuta

   Plants in rather loose tufts, glossy green to brownish green or blackish with red stems, to 50 mm high. Leaves straight to obscurely falcate secund, erect spreading when moist, little changed upon drying, grooved distally but not sharply keeled, not fragile. Larger stem leaves to 2.5 mm long, with an ovate to obovate, loosely sheathing base which more or less gradually contracts to a subulate composing up to 4/5 of the total leaf. Lamina cells of leaf limb rather thick walled, very irregular in size and shape, mostly rectangular but occasionally even quadrate, to 6 µm wide, smooth throughout. Median cells of sheathing base in regular rows, rectangular, to 7 µm wide, to about 8: 1, rectangular, thick walled and somewhat pitted with lumen: wall ratio about 1: 1, much shorter and somewhat wider near margin. Marginal cells of leaf base longer and narrower than adjacent interior cells sometimes resembling a limbidium which may extend above mid-leaf. Alar region very strongly demarcated in an auricle which may be left on stem with careless dissection. Alar cells often thin-walled and hyaline but mostly rather thick walled, not extending to costa, quadrate and red brown, to 25 µm wide. Supra-alar cells quadrate to transversely elongate in several rows, usually more pigmented and thicker walled than the alar cells. Costa well demarcated from base to apex in the distal 1/2 of the expanded leaf base, long excurrent and occupying most of the awn. Costa cross-section homogeneous, with walls of component cells moderately thickened. Margin plane to erect, entire throughout or more commonly slightly serrulate near apex. Axillary hairs to 125 µm, 4–6 celled, with one very short basal brown cell not offset. Rhizoids red-brown, to 12 µm wide at base, smooth, very sparsely produced and restricted to the stem base. Stem cross-section with no central strand, and with even the outer cortical cells rather large, but somewhat pigmented.

   Autoicous with perigonia axillary near the perichaetia. Perichaetial leaves abruptly contracted to an awn 1–2 times as long as the convolute sheathing base. Monosetous with the seta to 5 mm, yellow to brownish, straight and smooth throughout or with slight twists distally. Urn erect and oblong, to 1.5 mm long, only a little longer than wide, smooth to wrinkled except at the somewhat sulcate base, obscurely to not at all strangulate. Operculum rostrate, about 2/3 as long as the urn with cells of the flaring base isodiametric and rather thick walled, abruptly differentiated on beak into much elongated cells. Exothecial cells to 15 µm wide, to 3: 1, irregular in size and shape, not in vertical rows, mostly isodiametric with angular lumens, thick walled with lumen: wall ratio about 3: 1. Exothecial cells near mouth of capsule reddened and transversely elongate, 1/3–1/2: 1, in 2–4 rows. Annulus of 1–2 rows of thin walled, transversely elongate cells, persistent. Stomates few, on lower part of urn. Peristome smooth on both surfaces, red brown, somewhat perforate but not bifid, to 200 µm long, inserted somewhat below mouth, red-brown, inserted below capsule mouth, erect when dry. Dorsal plates of peristome vertically striate but ventral plates and peristome apex papillose. Spores spherical, smooth, to 15 µm.

Vouchers: Alpine Co.: Winnemucca Lake, Mokelumne Wilderness, Eldorado National Forest, Norris 71263; Humboldt Co.: South Fork of Tish-Tang-a-Tang Creek east of Hoopa, Norris & Whittemore 52413; Inyo Co.: Treasure Lake, John Muir Wilderness, Inyo National Forest, Norris 71529; Siskiyou Co.: South Sugar Lake, Klamath National Forest, Norris & McGrew 45644; Tulare Co.: Forest Road 14S11 near bridge crossing of Big Meadows Creek, Sequoia National Forest, Shevock & York 13677; Tuolumne Co.: near Olmstead Point, Yosemite National Park, Kellman 504 (CAS).

Literature: Crum and Anderson 1981; Holmberg 1969; Kellman 2003; Koch 1950a, 1951e, 1958; Koch and Ikenberry 1954; Lawton 1971; McGrew 1976; Showers 1982; Thomson and Ketchledge 1958.

Illustration References: Malcolm et al. 2009 p. 81; Abramov and Volkova 1998; Crum and Anderson 1981; Ignatov and Ignatova 2003; Ireland 1982; Lawton 1971.

Elevation by latitude plot for Blindia acuta
   in California