Creeping Feather Moss

Amblystegium serpens

Amblystegium serpens (Hedw.) B.S.G., Byrol. Eur. 6:53, 1853 (fasc. 55–56, Mon. 9.3).

Hypnum serpens Hedw., Sp. Musc. 268, 1801. [Original material: England, coll. Dillen.]

Very small, slender, yellowish green plants, with irregularly pinnate, often erect branches. Leaves to 1.0 mm long, 0.4 mm wide, being smaller on branches, appressed or erect-spreading, slightly more spreading when moist, slenderly acute or acuminate; margins serrulate distally; costae ending near midleaf; median cells of lamina 15–20 μm long, 5–7 μm wide, some very slightly papillose at upper ends; alar cells subquadrate, 7 μm wide, 7–10 μm long. Autoicous. Setae ca. 7 mm long. Capsule urn ca. 1.0 mm long; peristome with cilia in groups of 1–3; spores 11–15 μm in diameter, nearly smooth.

MAS A TIERRA: West slope of Cordon Salsipuedes, ca. 1800 ft, H. & E. 309 part.

The species is distributed over most of the north temperate region and in New Zealand and the Falkland Islands to the south. It has not been previously reported from Juan Fernandez. The Juan Fernandez material has many parts (such as leaf cells, setae, and capsules) about half the size given for A. serpens. The species usually has leaf cells 30–110 μm long, setae 1.0–1.5 cm long, and capsule urns 1.5–2.0 mm long. Some distinction may eventually be necessary.