Scleropodium cespitans

Plants medium-sized, in moderately dense mats, green to brownish. Stems to 10 cm, leafy shoots (0.4–)0.6–0.9 mm wide, branches moderately or sometimes strongly julaceous. Stem leaves closely imbricate, ovate, 0.8–1.6 × 0.3–0.8 mm, length to width ratio 1.6–2.6:1; margins weakly serrulate to subentire proximally, serrulate near apex; apex acute or very short-acuminate; alar cells enlarged, 10–14 µm, walls thin, region small, distinctly delimited; laminal cells 30–65 × 4–6 µm; basal juxtacostal cells quadrate to short-rectangular, 10–20 × 7–10 µm. Seta to 1.2 cm, strongly to moderately rough throughout. Capsule suberect to inclined. Spores 13–16 µm.

Habitat: Tree bases, tree roots, rotten logs, rock
Elevation: low to moderate elevations (0-1300 m)

Alta., B.C., Ariz., Calif., Oreg., Wash., w Eurasia, n Africa, Atlantic Islands.

Discussion

A number of characters separate Scleropodium cespitans from the widespread S. touretii, but when the latter is represented by small plants, then the most reliable distinction is characters of the leaf base: basal cells in S. cespitans are reduced, and when the leaf separates only small remains of cells remain on the stem, whereas S. touretii has long and stiff basal cells, considerable portions of which are left on the stem when the leaf is detached (a similar pattern is commonly seen in Homalothecium). Also, stems of S. cespitans are usually more slender than those of S. touretii, with branches often much thinner than the stems, 0.4–0.5 mm wide. The basal juxtacostal cells are not pigmented, in two or three rows; the laminal cells have obtuse angles.

Selected References

None.

Lower Taxa