Grimmia ovalis (Hedw.) Lindb., Act. Sci. Soc. Fenn. 10: 75. 1871. -- Dicranum ovale Hedw., Spec. Musc. 140. 1801. -- Grimmia ovata Web. & Mohr, Natur. Reise Schwedens 132. 1804. -- Grimmia commutata Huebn., Musci Germ. 185. 1833.

   Plants to 2.5 cm high, in hoary olive green to dark green tufts, sometimes nearly black below. Leaves imbricate when dry, erect to erect spreading when moist, concave but not at all keeled, to 3.5 mm long with the awn constituting up to 1/4 of that length, lanceolate to ovate lanceolate, about 3–5: 1. Median leaf cells unistratose below but bistratose in distal portion of leaf, smooth, to 10 µm wide, isodiametric with nearly regular lumens. Marginal cells more narrow but not otherwise differentiated. Basal juxtacostal cells rectangular, to 8: 1, to 10 µm wide, with lateral walls rather thick and pitted. Basal marginal cells quadrate, similar and contiguous to those of the median lamina. Costa percurrent in the somewhat acuminate apex. Costa cross-section about 2: 1 at leaf middle, with a prominent abaxial stereid band and with a single layer of larger cells on the adaxial face. Margin plane to incurved, entire below but serrulate to dentate on the awn, bi- to tri-stratose near the apex. Rhizoids red brown, to 15 µm wide at base, smooth. Stem cross-section with a central strand, a several layer thicker, pigment stereome and with leptodermous, hyaline and larger inner cortical cells. Gemmae not seen in our specimens.

   Dioicous with male and female plants similar. Perichaetial leaves larger and with a relatively longer awn than the adjacent vegetative leaves. Seta to 3 mm long, yellow to pale brown, straight even when moist, smooth. Urn erect, symmetrical, smooth to lightly sulcate when dry, to 1.5 mm long, about 1.5: 1, not strumose. Operculum rostrate, about 1/2 as long as urn. Annulus differentiated, not revoluble. Calyptra mitrate, lacerate at base. Peristome red-brown, to 200 µm long, cribrose along median line, papillose. Exothecial cells to 25 µm wide, not in regular vertical rows, quite irregular in size and shape, rectangular 2–4: 1, rather thick walled. Stomata phaneroporous, restricted to base of urn. Spores smooth, to 12 µm.

Vouchers: Fresno Co.: LeConte Canyon, Middle Fork Kings River, Kings Canyon National Park, Shevock & Haultain 18626 and north of Shaver Lake along Forest Highway 8, Sierra National Forest, Shevock & Norris 19794 (determined by Muñoz); Inyo Co.: South Fork Hanaupah Canyon, east base of Telescope Peak, Death Valley National Park, Shevock & York 21358; Mariposa Co.: Highway 120 near Yosemite Creek Campground, Yosemite National Park, Shevock 18483 (determined by Muñoz); Santa Cruz Co.: China Grade, Big Basin Redwoods State Park, Kellman 1293 (CAS, MA) [determined by Muñoz]; Tulare Co.: lower end of Crabtree Meadows west of Mt. Whitney, Sequoia National Park, Shevock 18549 (determined by Muñoz); Tuolumne Co.: Highway 108, 6.1 miles east of Mi-Wok Ranger Station, Stanislaus National Forest, Shevock 18587 (determined by Muñoz).

Literature: Crum and Anderson 1981; Harthill et al. 1979; Kellman 2003; McCleary 1972; Sayre 1951. As Grimmia commutata Lesquereux and James 1884.

Illustration References: Allen 2002; Flowers 1973; Greven 2003; Ignatov and Cao 1994; Ignatov and Ignatova 2003; Lawton 1971; Muñoz 1999a; Sharp et al. 1994; Smith 1978.

Elevation by latitude plot for Grimmia ovalis
   in California