4. Encalypta rhaptocarpa Schweagr., Sp. Musc. Frond., Suppl. 1. 1:56. 1811.
Plants small, 0.5–1.0 cm high, green or yellowish green, in tufts. Stems simple; central strand not well developed. Leaves twisted when dry, erect-spreading when moist, 2.1–3.5 mm long, oblong-ovate, oblong-lingulate to spathulate, apex broadly rounded, muticous or hair-pointed; margins plane; costa stout, ending below the apex, percurrent or excurrent; upper cells rounded to quadrate, 8–25 µm wide, densely papillose, obscure; basal cells oblong, 26–70 µm x 8–26 µm, with reddish, distinctly thickened transverse walls, several rows of marginal cells linear, 26–65 µm x 5–11 µm, thin-walled and pale. Autoicous. Perichaetial leaves similar to upper stem leaves. Setae yellowish to reddish brown, 1.5–7.0 mm long, erect, twisted above when dry; capsules cylindric, ca. 1.5–4.5 mm long, smooth or with dark reddish, longitudinal ribs; peristome teeth absent or single, lanceolate, pale golden, densely papillose; annuli undifferentiated; opercula with a long, straight beak. Calyptrae cylindric, smooth, reaching the base of capsules, with a rostrum 0.2–0.3 length of calyptra, basal margins somewhat irregular. Spores 24–35 µm in diameter, nearly smooth on proximal surface, with large warty papillae on distal surface.
Chinese specimens examined: GANSU: Mt. Qi-lian, Z.-X. Tan s.n. 3 VI. 1982 (IFSBH); Yu-zhong Co., L.-X. Zeng 18 (PE). HEBEI: Bei-tai Co., Q.-W. Wang 951 (IFSBH, PE). NEI MONGOL: Mt. Helan, Z.-G. Tong 2025, 2145 (IFSBH), D.-B. Jin 1963 (IFSBH); Mt. Da-qing, Z.-G. Tong 1619 (IFSBH). QINGHAI: Nang-qian Co., B.-C. Tan 95-158 (FH, MO); Qi-lian Shan (Mt.), Y.-Z. Wu 418-2 (IFSBH, PE). SHANXI: Ning-wu Co., C. Gao 30811 (IFSBH). SICHUAN: Markham (Ma-er-kang) Co., Allen 6991 (MO); Song-pan Co., Redfearn 35454 (MO, NY, SMS). TAIWAN: Kao-hsiung Co., T.-Y. Chiang 17333 (Herb. D. G. Horton). XINJIANG: Ku-che Co., 951211 (MO); Tashikuer, Y. Xia 035 (IFSBH); Urumqi Co., S. He 951018 (MO). XIZANG: Ben-ge Co., K.-Y. Lang 1251, 1313 (PE); Cao-ji Co., J.-D. Wang 97 (PE); Gela, M. Zang 29 (HKAS); Ghashan (Mt.), M. Zang 76-58 (HKAS); Nie-la-mu Co., S.-K. Chen 98 (IFSBH, HKAS); Tu-men, J.-Q. Yang 2436 (IFSBH). YUNNAN: Zhong-dian Co., J.-K. Yang 81-1278 (IFSBH, KUN).
Habitat: on soil slopes or thin soils over rocks, sometimes in low wetland; Distribution: China, Japan, North and Middle Asia, Europe, North America, Iceland, and Greenland.
The Chinese material of this species includes both Encalypta rhaptocarpa s. str. and E. rhaptocarpa s. lat. Encalypta rhaptocarpa s. str. is characterized by its oblong-ovate to spathulate leaves, with long, hyaline or yellowish hair-points, its capsules with prominent, longitudinal plicae and more or less reddish ribs, its reddish single peristome teeth, its calyptrae with rostrum 1/4 –1/3 the length of the calyptra, and its spores with warty protuberances on the distal surface. A distinctive form of E. rhaptocarpa s. lat. that occurs in China is differentiated from E. rhaptocarpa s. str. by longer capsules (3–4 mm versus 1.5–2.5 mm) and calyptrae (6–7 versus 4–5 mm), and the lack of a peristome. This species has been reported from China as E. spathulate (X.-L. Bai 1987), but the plants and the capsules of the latter are considerably smaller and shorter, and its calyptrae generally have a short fringe.
Illustrations: T. Cao, Horton & C. Gao 1992 (fig. 7, 1–9).