Hennediella heimii (Hedw.) R.H. Zander
Plants small, forming dense to loose turfs, green yellowish to orange or brownish. Stems 0.1-0.8 cm high, simple or branched. Leaves appressed to individually twisted or slightly incurved when dry, erect-patent to spreading when wet, oblong-elliptic to ovate or ovate-lanceolate, rarely lingulate, (0.7)1.2-2.5(3.8) mm long, (0.4)0.5-0.7(0.9) mm wide, apex obtuse to acute; margins plane, denticulate or dentate by 1-7 teeth per margin, sometimes entire, unistratose; costa ending 3-6 cells below the apex, percurrent or excurrent in a short mucro; in cross-section usually semicircular, with 2(4) guide cells, in 1(2) layers, and 2-4 rows of dorsal stereids; upper and median cells quadrate-hexagonal to rectangular, sometimes rounded or rhomboidal, (7.5)12.5-22.5(40) µm long, (7.5)12.5-17.5(20) μm wide, smooth or with low and simple papillae, marginal cells usually forming a border, 1-5(7) rows of rectangular or linear cells at midleaf, (7.5)15-25(45) µm long, (2.5)7.5-10(17.5) μm wide [ratio length/width 1-3.5(11)]. Autoicous, synoicous, heteroicous. Setae (4)6-12(24) mm long. Capsules exserted; urn cylindrical to ovoid-cylindrical or turbinate, (0.8)1.3-1.7(3) mm long; opercula rostrate to rostelate, (0.4)0.6-1.1(1.8) mm long, systylius, in straight rows; peristome absent. Spores (20)22.5-32.5(40) μm in diameter.
Ecology. Puna; along streams, on soil. Elevation. 3780-4380 m. Distribution. Bolivia: Oruro, Potosí. World range: widespread, in the tropical Andes known from Peru to Bolivia and northwest Argentina.
Some Bolivian specimens exhibit longer leaves and more linear and narrower middle marginal cells than typical H. heimii. However, it can be easily distinguished of other Andean species by its leaves scarcely dentate, with smooth or inconspicuous papillae in upper and median laminal cells and the opercula which remains attached to the columella for sometimes after the spores mature.
Specimens. Oruro: Cano & Jiménez 3745 (LPB, MUB); Potosí: Sanjines 4161 (LPB, MO, MUB).