Encalypta tianschanica, a new Chinese endemic from Xinjiang province, is described, illustrated, and compared with E. buxbaumioidea T. Cao, C. Gao & X.-L. Bai, an Inner Mongolian endemic that has narrowly pyriform capsules and a strongly excurrent costa. The new species is distinguished by its ovoid capsules, which are abruptly contracted to a very small mouth, and by its costa ending well below the leaf apex. The presence of distally warty spores places the new species in section Rhabdotheca C. Muller. A key to the six species of Encalypta Hedwig in Xinjiang is included. While working through our bryophyte collections made in Xinjiang Urgur Autonomous Region (Xinjiang), we encountered an interesting moss that belongs to Encalypta. This discovery has led us to present the following discussion on the genus. The genus Encalypta is characterized by a prominent and usually persistent, campanulate, non-plicate calyptra covering the whole capsule, by quadrate upper leaf cells that are obscure with dense papillae, and by elongate basal leaf cells that are often reddish with markedly thickened transverse walls. The species of Encalypta are predominantly distributed in the Northern Hemisphere, where they are characteristic components of northern and montane vegetation. In a world-wide revision of the Encalyptaceae, Horton (1982, 1983) accepted 19 species and 4 subspecies in Encalypta. Six or seven species were recognized from China by T. Cao et al. (1992) and T. Cao and C. Gao (1996), respectively, although Redfearn et al. (1996) listed eleven species of Encalypta from China. Encalypta sibirica (Weinmann) Warnstorf was reported as new to China by Horton (1983), but it was not included in T. Cao and C. Gao (1996). The latter study, however, includes two previously untreated species, Encalypta spathulata C. Muller and E. vulgaris Hedwig, by T. Cao et al. (1992). Tan et al. (1995) reported five species of Encalypta from Xinjiang. Unlike other Chinese species, which tend to have excurrent or at least percurrent costae and cylindric or pyriform capsules that are not contracted or only gradually contracted to a small mouth, the new collection we made in the Tianshan Mountains has costae ending well below the leaf apex and ovoid capsules that are abruptly contracted to a small mouth. This moss does not match any of the species already described from China (T. Cao et al., 1992; T. Cao & C. Gao, 1996), nor is it identical to any other species of Encalypta reported for Xinjiang (Tan et al., 1995). It is described below as a new species. Encalypta tiansehaniea J.-C. Zhao, R.-L. Hu & S. He, sp. nov. TYPE: China. Xinjiang: Tianshan Mountain Range, Guongnes forest station, near Guongnes river, 43?15'N, 84?45'E, J.-C. Zhao 953288-b, 30 July, 1995 (holotype, HBNU; isotypes, HSNU, MO). Figures 1-12. Plantae Encalyptae buxbaumioideae T. Cao, C. Gao et X.-L. Bai similis. Differt ab E. buxbaumioidea foliis et capsulis. Folia obtusa vel late rotunda, costa supene angusta, longe infra apiceum folii evanida. Capsula ovoidea vel ovato-oblonga, symmetrica, ca. 1.7-1.9 mm longa et ca. 1.0-1.11 mm crassa. Plants small, to 6-8 mm tall, green to yellowish green above, bright brown below, in dense tufts. Stems simple or sparsely branched; central strand indistinct. Leaves slightly tortuose when dry, erectspreading when moist, 2.2-3.5 mm long, obovate or spatulate, abruptly narrowed to a hyaline hairNOvoN 7: 320-322. 1997. This content downloaded from 157.55.39.185 on Thu, 26 May 2016 06:00:04 UTC All use subject to http://about.jstor.org/terms Volume 7, Number 3 Zhao et al. 321 1997 A New Chinese Moss Species