Claopodium crispifolium, Rev. Bryol. 20: 16. 1893. -- Hypnum crispifolium Hook., Musci Exot. Pl. 31. 1818. -- Hypnum ramulosum Hampe in C. Muell., Syn. 2: 486. 1851.

   Plants to 10 cm long in dense, pinnately branched, green to golden green mats. Stems well differentiated from the short branches whose leaves are markedly smaller. Stem leaves to 2 mm long, 2.5–3.5: 1, lanceolate and narrowly tapered from immediately above the auriculate base to the flexuose and hyaline acumen. Leaves, when moist, spreading at the base, then erect and overlapping, strongly catenulate when dry. Margins plane, coarsely dentate on the auricle but serrulate above. Median cells mostly elliptic to rhomboidal with small corner thickenings, 6–8 µm wide, 1–2.5: 1, high unipapillose on both surfaces with the papillar salients up to 6 µm high and covering most of the lumen. Juxtacostal cells, especially the basal, smooth, to 5: 1, thick-walled and somewhat pitted. Marginal cells in one to several rows smooth and short rectangular, to 3: 1, especially well-defined near median leaf. Cells of piliferous apex very long and hyaline, more than 10: 1. Cells in the auricle mostly smaller and more regularly quadrate than the median cells. Costa pale and glistening in macroscopic view, ending near the base of the hyaline acumen, sparingly prorate spinose. Axillary hairs not offset from leaf insertion, to 120 µm long, 3 celled, without a basal brown cell. Pseudoparaphyllia arched over bud, broadly triangular to orbicular, very coarsely serrate, high papillose. Rhizoids red-brown and smooth, densely fascicled and essentially unbranched, to 8 µm wide at insertion.

   Dioicous with male plants somewhat smaller than the females. Perichaetia on main stems with bracts very pale to bleached green, somewhat longer than vegetative leaves. Seta red brown, papillose throughout, to 2 cm long. Urn red brown, inclined to horizontal, oblong and asymmetric, to 2: 1, to 2 mm long, strangulate when dry. Operculum rostrate, about as long as urn. Exothecial cells short rectangular, 1.5–2.0: 1, to 30 µm wide, rather thick walled with strong corner thickenings, Annulus well differentiated, not revoluble. Exostome to 500 µm long, brown to pale brown, evenly tapered and without a shoulder, horizontally striate at base, nearly smooth distally. Endostome almost as long as exostome, with basal membrane comprising about 1/2. Endostome processes lightly papillose, keeled and perforate, with 2–3 cilia. Spores smooth, to 12 µm in diameter.

Vouchers: Del Norte Co.: South Fork Smith River about 3 miles from Big Flat, Norris 74237; Marin Co.: Cataract Trail near Alpine Lake, Yurky 403 (SFSU); Mendocino Co.: Fox Creek, Branscomb Reserve, Norris 47188; San Mateo Co.: Pilarcitos Canyon below Lake Pilarcitos, Steere s.n. (UC); Shasta Co.: Damnation Pass Road at Lunch Gulch, Norris & Hermann 22563; Trinity Co.: Highway 36 at Clear Creek about 3 miles west of Forest Glen, Norris 68729.

Literature: Bourell 1981; Holmberg 1969; Jamieson 1969; Koch 1950a; Koch and Ikenberry 1954; Lawton 1971; Lesquereux 1868; Noguchi 1964; Spjut 1971; Yurky 1990, 1995. As Hypnum crispifolium Sullivant 1856; Watson 1880.

Illustration References: Malcolm et al. 2009 p. 249; Lawton 1971; Noguchi 1964.

Elevation by latitude plot for Claopodium crispifolium
   in California