Homalothecium californicum
Bryologist 112: 595, fig. 2. 2009.
Plants large, in moderately dense tufts, green, occasionally brownish with age. Stems to 15 cm, regularly pinnate, branches to 10 mm, circinate when dry. Stem leaves erect when dry, ovate-lanceolate, 2–2.8 × 0.8–1.2 mm; base slightly narrowed, narrowly decurrent; margins plane or recurved, serrulate or entire; apex acuminate; costa to 70–90% leaf length, terminal spine absent; alar cells ovate, 6–9 µm wide, walls thick, region of 15–25 × 15–25 cells, distinctly delimited, opaque to moderately translucent; laminal cells elongate, 30–65(–80) × 4–8 µm; basal cells irregularly long-ovate, region in 2–5 rows, indistinctly delimited from distal cells. Branch leaves erect-appressed when dry, erectopatent when moist, ovate-lanceolate or triangular-lanceolate, 1.8–2.5 × 0.7–0.9 mm; margins recurved almost throughout, serrulate to entire; apex gradually tapered or broadly acuminate; costa to 70–100% leaf length, terminal spine absent; alar cells ovate, 6–9 µm wide, region of 10–15 × 10–18 cells, distinctly delimited; laminal cells elongate, 30–60 × 4–7 µm; basal cells in 1–3 rows; distal cells smooth. Sexual condition phyllodioicous. Seta 1.1–1.7 cm, rough. Capsule erect or nearly so, cylindric, straight, 3–4 mm; annulus unknown; operculum unknown; peristome xerocastique; exostome teeth striolate proximally, papillose distally; endostome basal membrane high, segments as long as exostome teeth, narrow, cilia short, less than 1/4 segment length. Spores 16–21 µm.
Habitat: Rock, limestone, granite, basalt, serpentine, soil, litter in conifer and broad-leaved deciduous forests, mesic conditions
Elevation: moderate to high elevations (400-1600 m)
Discussion
Homalothecium californicum was described only recently, although its distribution is well documented by specimens from 14 counties in California. The plants are rather robust, although smaller than H. megaptilum, usually green, but not very pale yellowish to whitish as is the latter. Gradually acute branch leaves provide a certain similarity to H. nevadense, which sometimes also has a frondose appearance and erect capsules; H. nevadense differs primarily in smaller size and fewer stem leaf alar cells, regions of 5–10 × 6–10 cells versus 15–25 × 15–25 in H. californicum. The sporophytes are infrequent.
Selected References
None.