Haplodontium altunense X.R.Wang & S.Mamtimin, 2021

Wang, Xiao-Rui, Li *, Min, Spence, John R., Zhao, Jian-Cheng & Mamtimin, Sulayman, 2021, Haplodontium altunense (Bryaceae, Bryopsida), a new moss species from Northwest China, PhytoKeys 183, pp. 9-19 : 9

Haplodontium altunense X.R.Wang & S.Mamtimin sp. nov.

Figs 1 , 2 , 3

Type.

China. Xinjiang, Ruoqiang County, Altun Mountain National Nature Reserve , 37°0.42'N, 88°36.35'E, 4290 m a.s.l., 22 July 2011, S Mamtimin 16752 (holotype: HBNU!; isotype: XJU!) .

Diagnosis.

Particularly distinctive features of the new species including: double peristome; the exostome has raised and membranous chomata with united lamellae between two teeth proximally; the endostome is poorly developed and all the endostomial material tightly adherent to the exostome.

Description.

Plants small, soft and dull, brown-green. Stems short, 2.5-6 mm high, weakly julaceous, branched, circular or pentagonal circular in transverse section with small and thick-walled peripheral cells surrounding 2-3 layers gradually larger and thin-walled cortical cells, central strand weakly developed. Leaves imbricate when dry, erect when moist, enlarged towards stem apex, ovate to broadly ovate, concave, 0.5-1.1 × 0.3-0.7 mm; base not decurrent; margins plane or recurved medially, 1-stratose, limbidium absent, smooth or finely serrulate distally; apex broadly acute; costae not reaching apex, guide cells weakly developed, 2-4 in one layer in costal transverse section, ventral and dorsal stereid bands present; alar cells not differentiated from juxtacostal cells; laminal cells lax; distal laminal cells rhomboidal, 30-44 × 11-21 μm, with slightly thickened walls; medial laminal cells long rhomboidal to rectangular, 37-69 × 12-20 μm, somewhat narrower in 2 or 3 rows toward the margins but not forming a distinct border; proximal laminal cells long rectangular, 37-56 × 20-28 μm. Dioicous(?). Perigonia not seen. Perichaetia at the end of short, inconspicuous stems, appearing laterally because of well-developed innovations; perichaetial leaves larger than vegetative leaves. Setae single, light brown, 15-19 mm long. Capsules nutant and symmetric, reddish brown, obovoid, 1.5-2 mm, neck short and indistinct, mouth small, stomata abundant in the neck, superficial; opercula long-conic with short rostrate; annulus present, consisting of two rows of cells, revoluble and cells with slit-like lumen; peristome double, exostome inserted below the mouth, teeth lanceolate, red-brown and pored, raised and membranous chomata with united lamellae between two teeth proximally, pale yellow to hyaline and largely papillose along horizontal and median vertical lines distally; endostome poorly developed, basal membrane smooth, segments and cilia rudimentary, all the endostomial material strongly adhere to the exostome. Spores spherical, 20-22 μm in diameter, minutely papillose.

Etymology.

The specific epithet Haplodontium altunense refers to the type locality in Altun Mountain National Nature Reserve in the Northwestern China.

Distribution and habitat.

China (Xinjiang). Only known from the type locality, on soil substrates at 4290 m in the Altun Mountain National Nature Reserve. The population grows in a dry, cold, and windy habitat with intense evaporation. The companion species include some xerophytic mosses of the family Pottiaceae .

Chinese name.

阿尔金拟缺齿藓 ( ā ěr jīn nĭ quē chĭ xĭan)

Figures

Figure 1. Haplodontium altunense A plant (wet) B capsule (wet) C capsules (dry) D leaves E transverse section of leaf F superficial stoma G annulus growing on the capsule mouth H dorsal views of peristome I transverse section of stem J apical laminal cells and margin K apical laminal cells L median laminal cells M basal laminal cells. Drawn by Xiaorui Wang from the holotype (HBNU!).

Figure 2. Light micrographs of Haplodontium altunense A-C plants (dry) D Capsule (dry) E capsule (wet) F annulus growing on the capsule mouth G annulus falling off the capsule mouth H dorsal views of median peristome showing the large papillae along the horizontal and median vertical lines I dorsal views of distal peristome showing adherent endostomial material and exostome teeth J transverse section of stem K transverse section of midleaf L transverse section of costa M leaf apex N median laminal cells O basal laminal cells P leaves. Photographed by Xiaorui Wang from the holotype (HBNU!).

Figure 3. Scanning electron micrographs of Haplodontium altunense A dorsal views of peristome B dorsal views of peristome with annulus C dorsal surface of exostome teeth proximally showing the pores and the raised and membranous chomata horizontal lines with united lamellae between two teeth D dorsal surface of exostome teeth distally showing the large papillae along the median vertical lines E dorsal surface of exostome teeth distally showing the endostomial material adherent to the teeth F ventral views of peristome G ventral surface of peristome proximally showing the smooth endostome basal membrane H ventral views of peristome distally I, J ventral surface of peristome medially and distally showing the endostomial material adherent to the teeth K spore L exine ornamentation of spore. Photographed by Xiaorui Wang from the holotype (HBNU!).