Brachythecium bolanderi, Ber. S. Gall. Naturw. Ges. 1876–1877: 324. 1878. -- Hypnum bolanderi Lesq., Trans. Amer. Phil. Soc. 13: 12. 1865. -- Bryhnia bolanderi (Lesq.) Broth., Nat. Pfl. 1(3): 1158. 1909.

   Plants in soft, loose mats, pale green to olive-green, irregularly branched with the branches prostrate to ascending. Primary stems to 8 mm long with leaves somewhat larger than those on the branches. Branch leaves to 1.5 mm, about 2: 1, symmetric and straight without a laterally twisted acumen, only slightly concave near the base, not plicate, broadly ovate to ovate-lanceolate, weakly spreading wet or dry. Leaf apices narrowly acute to acuminate, only gradually narrowed. Margins somewhat recurved at base or completely plane, inconspicuously decurrent by 1 or 2 cells which remain on stem with dissection, serrate to prorate-serrate from base to apex. Median cells mostly smooth but with a number of prorate cells distally, spinulose and thin-walled, to 6 µm wide, mostly 4–6: 1, not pitted. Basal juxtacostal cells quadrate to short rectangular, thick walled and pitted, to 12 µm wide. Marginal cells of alar region short rectangular, to 10 µm wide, to 4: 1. Interior alar group poorly demarcated, with the cells quadrate, opaque-green and thick-walled, to 10 µm wide. Costa extending to the base of the acumen, tapering to apex, spinose at apex. Juvenile leaves to 100 µm long, deltoid-triangular, nearly as long as wide, coarsely serrate across the acute apex. Axillary hairs fugaceous, extremely small, to 20 µm long, 2 celled with a single basal brown cell, and with the distal cell thin-walled and slightly clavate. Rhizoids densely fasciculate on the abaxial leaf base, smooth and red-brown, to 6 µm wide at insertion, long and monopodially branched. Stem cross-section with central strand, a stereome 2–5 cells thick poorly differentiated from the only gradually larger- and thinner walled cells of the medulla.

   Dioicous with male plants typically somewhat smaller than the females. Perigonia sparingly produced on prostrate stem and large branches. Perichaetial leaves 4–6 mm long, ecostate, sheathing at base but reflexed distally. Seta coarsely papillose throughout, 10–15 mm long, erect or distally geniculate. Capsule dark brown to reddish brown, inclined, not distorted or sulcate when dry. Urn arcuate and asymmetrical, to 1.5 mm, about 2: 1. Exothecial cells irregular in size and shape, 15–30 µm wide, 1–5:1, with elongate cells typically alternating with shorter cells in vertical rows. Operculum conic, 1/4 to 1/3 as long as urn. Annulus present, of several rows of quadrate and thick-walled cells. Stomata present on slightly raised pustules at base of capsule, short and vertical pored. Exostome teeth narrowly lanceolate, about 10: 1, strongly papillose, white, erect when dry. Endostome segments very narrow, about half as long as exostome and with no basal membrane. Cilia 1–2, narrow and appendiculate. Spores smooth to inconspicuously papillose, 9–12 µm.

   It is no accident that this extremely small Brachythecium was placed by Brotherus (1909) in Bryhynia. The frequency of prorate cells plus the constant presence of strongly prorate serrations on the leaf margins strongly suggest such a placement. The pattern of strong serrations to the base combine with the almost non-decurrent and non-plicate leaves in this very small plant to render it easy to identify.

Vouchers: San Luis Obispo Co.: Queen Bee Campground about 1 mile from La Panza Summit, Norris 55184; Santa Cruz Co.: Fall Creek, Henry Cowell Redwoods State Park, Kellman 661 (CAS); Shasta Co.: Pit River at Potem Falls northwest of Round Mountain, Norris 76324; Siskiyou Co.: shores of Castle Lake southwest of Shasta City, Shasta-Trinity National Forest, Norris 99777, Trail Gulch Lake west of Callahan, Klamath National Forest, Norris 102544 and 1 mile west of Elk Lick, Klamath National Forest, Norris 23206; Sonoma Co.: Duran County Park near Bodega Marine Laboratory, Norris 103496; Tulare Co.: slopes above Oriole Lake, Sequoia National Park, Shevock 17634.

Literature: Harthill et al. 1979; Howe 1896; Kellman 2003; Kingman 1912; Koch and Ikenberry 1954; Lawton 1971; Long 1978; McGrew 1976; Showers 1982; Toren 1977. As Hypnum bolanderi Lawton 1965b; Lesquereux 1868; Watson 1880.

Illustration References: Lawton 1971.

No illustrations found in database.

Elevation by latitude plot for Brachythecium bolanderi
   in California