Brachytheciastrum velutinum

(Hedwig) Ignatov & Huttunen

Arctoa 11: 260. 2003.

Illustrated
Basionym: Hypnum velutinum Hedwig Sp. Musc. Frond., 272. 1801
Treatment appears in FNA Volume 28. Treatment on page 412. Mentioned on page 409, 411, 413, 414, 416.

Plants small, in loose or moderately dense tufts, green to yellowish or brownish. Stems to 4(–5) cm, creeping or ascending and erect, terete- to subcomplanate-foliate, not julaceous, regularly or irregularly pinnate, branches to 4(–6) mm, terete- or subcomplanate-foliate. Stem leaves erect to erect-spreading, densely to loosely arranged, falcate to circinate, ovate-lanceolate to lanceolate, not plicate or with 2 submarginal plicae, rarely with additional indistinct plicae, 1–1.8 × (0.1–)0.2–0.5(–0.6) mm; margins plane or recurved at base, serrate, serrulate, or subentire; apex gradually long-acuminate, acumen weakly spreading; costa to 40–70% leaf length, often thick distally, terminal spine present; alar cells subquadrate to short-rectangular, 8–12 × 10–15 µm, region small, of 4–8 × 4–6 cells, distinctly delimited; laminal cells linear, 45–140 × 4–7 µm; basal cells short-rectangular, 8–10 µm wide, region in 1 or 2 indistinctly delimited rows. Seta red-brown, 0.8–1.5 cm, smooth, rough, or rough proximally and smooth near capsule. Capsule horizontal, brown, dark red-brown with age, elongate, to 1.5 mm; endostome basal membrane 1/3–1/2 endostome length, cilia as long as segments. Spores 10–14(–15) µm.

Distribution

V28 639-distribution-map.gif

North America, Eurasia, n Africa, Atlantic Islands.

Discussion

Varieties 2 (2 in the flora).

Plants of Brachytheciastrum velutinum have less strongly plicate branch leaves than stem leaves.

Selected References

None.

Key

1 Setae rough throughout; branches subcomplanate-foliate; branch leaves ± falcate or occasionally straight; stem leaves 1-1.6 mm; plants green, sometimes yellowish or brownish; laminal cells 45-90(-125) × 5-7 µm; widespread. Brachytheciastrum velutinum var. velutinum
1 Setae slightly rough proximally and smooth near capsule, or smooth throughout; branches terete- or rarely subcomplanate-foliate; branch leaves straight; stem leaves 1.2-1.8 mm; plants green to golden brown; laminal cells (60-)80-140 × 4-5µm; w United States, Texas. Brachytheciastrum velutinum var. salicinum