Chimonobambusa sangzhiensis (B.M.Yang) N.H.Xia & Z.Y.Niu, 2022

Niu, Zheng-Yang, Cai, Zhuo-Yu, Liao, Chun-Lin & Xia, Nian-He, 2022, Chimonobambusa sangzhiensis (Poaceae, Bambusoideae), a new combination supported by morphological and molecular evidence, PhytoKeys 195, pp. 127-141 : 127

Chimonobambusa sangzhiensis (B.M.Yang) N.H.Xia & Z.Y.Niu comb. nov.

Figs 2 , 3 , 4

Basionym.

Indosasa sangzhiensis B.M. Yang (1989: 333); Yang (1993: 90); Yi et al. (2021: 244).

Type.

China. Hunan: Sangzhi Xian, Badagongshan , el. 1570 m, 23 September 1965, Vegetation Survey Group 00549 (holotype: HNNU!) .

Note.

After examining the type specimen and other specimens collected from the type locality, we are able to provide a revised description of the morphology of this species below.

Description.

Small sized bamboo. Rhizomes leptomorph; internodes cylindrical, 4-angled when dry, 1.5-4 cm long, 5-8 mm in diameter, hollow, glabrous, walls ca. 1 mm thick; nodes flat, 1-3 roots at each node, glabrous; rhizome buds broad-ovate to subrounded, glabrous. Culms diffuse, erect, 1-3 m tall and 0.5-1.5 cm in diameter; internodes terete or base slightly 4-angled, with two longitudinal ridges and three grooves above branching points, 15-20(-24) cm long, densely white puberulent, especially below nodes, mid-culm internodes hollow, walls 1.5-3 mm thick, upper and basal internodes nearly solid; basal nodes without root thorns; supranodal ridges flat or slightly prominent at unbranched nodes, sheath scars prominent, corky, glabrous, intranodal regions 2-5 mm long, glabrous. Primary buds solitary, ovate, yellowish green, 5-8 × 3-5 mm, glabrous. Mid-culm branch complement with 3 branches, erect, subequal, inclined at an angle of 15°-45° with the culm, internodes 1.5-10 cm long, glabrous; supranodal ridges prominent; branch leaf sheaths thinly leathery, shorter than internodes, abaxially glabrous. Culm leaf sheaths long triangular, caducous, thinly leathery, 10-15 × 3.5-6 cm, 1/2-3/4 as long as internodes, pale brown, abaxially glabrous, longitudinal ribs conspicuous, upper parts of margins sparsely ciliate, deciduous when old; auricles absent; oral setae several, curly, scabrid, pale brown, 2-5 mm long, deciduous when old; ligules arcuate to truncate, 0.5-1.5 mm long, entire, densely ciliate; culm leaf blades erect, narrowly triangular or subulate, 4-11 × 1.5-4 mm, middle and upper parts involute, base extending broadly outward to join sheath apex, both sides glabrous, longitudinal ribs conspicuous. Foliage leaves 1-3 per ultimate branch; foliage leaf sheaths 3-4 cm long, initially purplish red, later becoming green, abaxially pubescent, glabrescent, margins ciliate, longitudinal ribs conspicuous; auricles absent; oral setae 3-5, curly, scabrid, 2-5 mm long; ligule truncate, ca. 1 mm long, entire or sparsely ciliate; pseudo-petioles 2-5 mm long, sparsely ciliate; foliage leaf blades lanceolate, papery, 9-19 × 1.2-2 cm, base widely cuneate, apex acute, abaxially glabrous, adaxially sparsely pubescent, glabrescent, margins serrulate, longitudinal secondary veins 3-5 pairs, transverse veins conspicuous. Inflorescence unknown.

Phenology.

New shoots produced during April to June.

Vernacular names.

Lěng Zhú (Chinese pronunciation), 冷竹 (Chinese name).

Distribution and habitat.

The species has only been found at its type locality so far and is rather common on mountains between elevations of 1600 m to 1900 m. It prefers a cold and moist environment and often grows under forest cover.

Additional specimen examined.

The same locality as the type, along the forest path, 29°40'43"N, 109°44'60"E, 1610 m, 29 June 2021, Z.Y. Niu NZY109 (IBSC).

Figures

Figure 2. The holotype of I. sangzhiensis B. M. Yang (HNNU).

Figure 3. Morphological characters of I. sangzhiensis A habit B culm leaf sheath on internodes covered with dense white pubescence C culm bud, node and sheath scar D two longitudinal ridges and three grooves above branches D, E branches at mid-culm nodes, young D and old E culm. All photos by Z. Y. Niu.

Figure 4. Morphological characters of I. sangzhiensis A culm leaf, detached B culm leaf blade C culm leaf ligule D ultimate leafy branches E foliage leaf oral setae F rhizome with partial young culms. All photos by Z. Y. Niu.