Lapland Yoke Moss

Plants small to medium-sized, up to 3.5 cm high, dark green or yellowish brown, in dense tufts. Stems erect, simple or forked, radiculose below. Leaves strongly curled and contorted when dry, narrowly oblong- to linear-lanceolate; margins irregularly and narrowly recurved below, entire or indistinctly sinuate above; costa single, strong, ending near the leaf apex, papillose on both sides; upper laminal cells rounded-hexagonal, 8–10 µm in diameter, thick-walled, very opaque, densely warty-papillose; lower cells slightly larger, rectangular, thin-walled, hyaline or pale yellowish, smooth; alar cells not differentiated. Autoicous. Perichaetial leaves greatly enlarged, entirely sheathing, broad at base, short-pointed at the apex. Setae up to 2 mm long, as long as or shorter than perichaetial leaves; capsules shortly emergent, 1.0–1.3 mm long. Spores 9–12 µm in diameter, usually smooth or nearly so.

Distribution: China, Japan, Central Asia, Europe, Greenland, Iceland, and North America.

Habitat: on moist rocks.

Amphidium sublapponicum (C. Müll.) Broth., Nat. Pflanzenfam. 1(3): 460. 1902. Zygodon sublapponicus C. Müll., Nuov. Giorn. Bot. Ital. n. sér. 5: 186. 1898. Type. China: Shaanxi, Taibai Shan (Mt.), Giraldi 1209 (holotype H). Synonymized by C. Gao (1994).

Amphidium lapponicum Schimp. Coroll. Bryol. Eur. 39. 1856
Anictangium lapponicum Hedw. Sp. Muse. 40. 1801.
Aniciangium striatum Brid. Muse. Recent. Suppl. 1: 25. 1806.
Zygodon lapponicus Bruch & Schimp. in B. S. G. Bryol. Eur. (4:) Zyg. 6. 1838.
Amphoridium lapponicum Schimp. Syn. 247. 1860.
Plants cespitose, dark green, brown to blackish below, 1-3 cm. high; leaves more or less crisped when dry, spreading when moist, 1.5—2 mm. long, narrowly oblong-lanceolate to linearlanceolate, sharply to obtusely acute at the apex, the margins plane, entire; costa strong, ending shortly below the apex, with 4 median guide cells; lamina mostly of one layer of cells; upper median leaf-cells roundish-quadrate, incrassate, 8-10 ^ in diameter, papillose on both sides with numerous low papillae; basal cells smooth, larger, rectangular, thinner-walled, pellucid to hyaline; perichaetial leaves very different, sheathing, entirely smooth, the upper more abruptly acuminate, often serrate at the base of the acuminatum, the upper cells elongate in all, rhomboidal to rhombic; autoicous; seta about 1.5 mm. long; capsules pyriform, about half-emergent, erect and symmetric, brownish and 8-ribbed when dry, more or less urceolate with a spreading mouth, the neck distinct, as long as the spore-sac; calyptra covering about half the capsule; operculum red, the beak usually less than the radius of the capsule; spores 10-12 m in diameter, maturing in spring or early summer.
Type locality: Lapland.
Distribution: Crevices of cool, moist, shaded ledges and cliffs in elevated regions, mostly on noncalcareous rocks; Greenland to British Columbia, south to California and Arizona, and the northern United States east of the Rocky Mountains ; Europe ; Asia.