Bryum gemmiparum DeNot.
Cronac. Briol. Ital. 1: 26: 1866. -- Bryum alpinum With. ssp. gemmiparum (DeNot.) Kindb.
Plants erect in green to brownish green wefts, to 2.5 cm high. Leaves concave, ovate lanceolate to lanceolate with narrowly obtuse apices, to 2 mm long, about 2.5–3.5: 1, erect to imbricate when moist, little changed upon drying, not plicate. Median laminal cells elongate-hexagonal with thin to somewhat thick walls (lumen: wall ratio 4–6: 1) 3–4: 1, completely smooth, not pitted, to 15 µm wide. Basal and alar cells shorter and broader than median cells. Margins decurrent by only 1–3 cells, plane above but usually with some basal recurvature, entire to minutely serrulate. Limbidium of narrowly rectangular cells but not clearly demarcated, unistratose throughout. Costa yellowish but somewhat reddened at base, percurrent or subpercurrent in the bluntly acute immediate apex. Costa cross-section with a well-demarcated dorsal and ventral epidermis, with a strongly developed abaxial stereid band and with only one layer of guide cells. Axillary hairs 2 cells long, to 200 µm, with a short but unpigmented basal cell and a much inflated and thin-walled terminal cell. Rhizoids papillose, brown, sparingly branched, surrounding an isodiametric macronematal area to 100 µm wide. Stem cross-section round, without a central strand, with hyaline and leptodermous inner corticals abruptly transitting to a single layer of only moderately pachydermous, red brown outer cortical cells, without a hyaloderm. Gemmae often present in upper leaf axils, short-elliptic with numerous erect juvenile leaves.
Dioicous with male plants similar to females. Perichaetial leaves similar to vegetative leaves. Seta red-brown, smooth, erect but geniculate distally, to 20 mm long. Urn to 3.5 mm long, short-cylindric, 2–2.5: 1, inclined to pendent, neither sulcate nor strumose. Operculum short conic. Annulus prominent, revoluble, with inflated and thin-walled cells. Exothecial cells at capsule mouth to 20 µm broad, transversely elongate in several rows. Exothecial cells at middle of urn rectangular, to 1–3: 1, to 22 pm broad, not in regular rows, evenly thick walled with lumen: wall ratio 2–4: 1. Stomates restricted to neck of capsule, raised on short pustules, round. Exostome yellow-brown, to 300 µm long, inconspicuously shouldered, lightly papillose with prominent dorsal lamellae. Endostome with basal membrane constituting about 1/2 of total length. Segments smooth to lightly papillose, about as long as exostome, narrowly perforated along keel with 1–2 appendiculate to nodose cilia. Calyptra cucullate, mostly shed before capsule maturity. Spores to 20 µm, finely papillose.
|Literature||Crum and Anderson 1981; Flowers 1973; Harpel 1980a; Harthill et al. 1979; Kellman 2003; Koch 1950a; Koch and Ikenberry 1954; Lawton 1971; Long 1978; Mishler 1978; Spence 1988a; Spjut 1971; Strid 1974; Toren 1977.|
|Illustrations||Crum and Anderson 1981; Flowers 1973; Lawton 1971; Smith 1978.|
|Notes||Needs update to Imbribryum gemmiparum (De Notaris) J. R. Spence.|
|Bioregions||CaR, CW, DMoj, DSon, MP, NW, SN, SW.|
|Vouchers||Del Norte Co.: Smith River about 10 miles east of Gasquet on Highway 199, Norris 8787; Lake Co.: Soda Creek near Lake Pillsbury, Mendocino National Forest, Toren 5131 (CAS); Modoc Co.: west side Goose Lake about 4 miles south of Oregon state line, Norris 18720; Plumas Co.: Highway 70 near Belden, Norris 69975; Riverside Co.: Lilly Creek, County Park near Idyllwild, San Jacinto Mountains, Harpel 1450 (pers. herb.); San Bernardino Co.: Cottonwood Wash, Granite Mountains, Mojave National Preserve, Laeger & Bucknar 1837 (CAS) [determined by Spence]; Shasta Co.: Highway 299 at Casberry Flat about 1 mile west of Hatchet Mountain Summit, Norris 68581 (determined by Spence).|