The following is from the California Moss eFlora. See here
Plants erect in small green to rather dark green tufts, to 5 mm high. Leaves spreading when moist but, when dry, loosely erect with apices not incurved. Leaves to 2.5 mm long, about 3: 1, ovate-lanceolate to lanceolate with obtuse to rounded but minutely apiculate apices. Median laminal cells isodiametric with rounded lumens, thick walled with strong corner thickening, to 18 µm wide, smooth or with 1–2 very low papillae on both surfaces. Basal juxtacostal cells pellucid and rectangular, 1.5–2.5:1, to 24 µm wide with lateral walls straight but somewhat unevenly thickened. Basal juxtamarginal cells isodiametric and similar to median laminal cells. Margins recurved from base to near the apex, entire or with a few serrulations at the extreme apex. Costa ending within about ten cells of apex, not situated in a keel. Costa cross-section homogeneous, at mid-leaf only 2 cells thick and up to 4 cells wide. Axillary hairs mostly rather uniform in size, to 5 cells and 100 µm long, with one basal brown cell, not offset from leaf insertion. Rhizoids abundant near base of plant but also present even on distal portions of plant, smooth, pale-brown to red-brown, to 30 µm in diameter at base, sparingly branched. Stem cross-section without a central strand, with hyaline inner corticals and with 1–2 layers of somewhat thicker-walled, red brown outer cortical cells. Gemmae scattered on adaxial leaf surface, to 25 µm in diameter, composed of 3–4 essentially isodiametric, green cells
Conrad, H., & Redfearn, Jr., P. (1979). How to know the mosses and liverworts. (2nd ed.). Dubuque, Iowa: Wm. C. Brown Company Publishers.
Crum, H. (1983). Mosses of the Great Lakes forests. (3rd ed.). Ann Arbor, Michigan: University of Michigan Herbarium.
Crum, H. A., & Anderson, L. E. (1981). Mosses of eastern North America. (Vol. 2). NY, New York: Columbia University Press.