Yushania tongziensis N.H. Xia, Y.Y. Zhang et G. Xie, 2023

Zhang, You-Yuan, Xie, Gang & Xia, Nian-He, 2023, Yushania tongziensis (Poaceae, Bambusoideae), a new bamboo species from north Guizhou, China, Phytotaxa 618 (1), pp. 86-92 : 87

Yushania tongziensis N.H. Xia, Y.Y. Zhang et G. Xie , sp. nov. ( Figure 1 , 2 & 3 )

Diagnosis. Yushania tongziensis is morphologically similar to Y. panxianensis T.P. Yi et J.J. Shi particularly in its culm internodes hollow, usually developing 3‒7 branches at mid-culm nodes, without longitudinal ridges and grooves above branching points, auricles of culm and foliage leaves absent, culm leaf blades reflexed and longitudinal secondary veins 3 or 4 pairs, but can be easily distinguished in having culm internodes smooth, deciduous culm leaf sheaths, oral setae absent, ligules ca. 1 mm tall (vs. 1.5‒3 mm), pseudopetioles 1‒1.5 mm long (vs. 1 mm) and transverse veins inconspicuous of leaf blade.

Type. CHINA, Guizhou: Tongzi County, Yaolong Mountain , 28°32’23”N, 106°47’58”E, 1790 m alt., 20 July 2022, Y. Y . Zhang ZYY-2022 (holotype: IBSC!, Bar code: IBSC0889717 ; isotype: IBSC!) .

Description. Shrubby bamboos. Rhizomes pachymorph, long-necked; neck 8–20 cm long, 0.4–0.5 cm in diameter, solid, internodes 0.7–1 cm long. Culms diffuse, erect, 0.7–1.2 m tall and 0.3–0.55 cm in diameter; internodes terete, 10–12 cm long, without longitudinal ridges and grooves above branching points, dark green, initially with thinly white powder, glabrous, hollow, wall 1.5–2 mm thick, pith lamellar; supranodal ridges prominent at each nodes; sheath scar prominent, with persistent remains of sheath base, glabrous, lower than supranodal ridges; intranodal regions 3–4 mm long, glabrous. Branching from third or fourth node (0.15–0.2 m) above the ground, mid-culm branches 3–7, ascending, subequal, 0.1–0.15 cm in diameter, hollow, inclined at an angle of 15–20° with the culm. Primary buds solitary, ovate-triangular, adnate to the internode surface, green, margins ciliolate. Culm leaf sheaths caducous, leathery, longitudinal ribs prominent, triangularly narrowly rounded, 2/3 to 4/5 as long as internodes, abaxially sparsely yellowbrown antrorsely setose, margins entire; auricles and oral setae absent; ligules truncate, ca. 1 mm tall, margins entire or shallowly serrate; blades reflexed, triangular lanceolate, ca. 1.2 cm long, involute, the base 1/3 to 1/2 as wide as the sheath apex, both sides glabrous. Foliage leaves 3–7 per ultimate branch; sheaths 3‒4.5 cm long, initially purplish red, later becoming pale brown, glabrous; auricles absent, oral setae 5 or 6, 2–4 mm long, erect, tardily deciduous; ligules truncate, ca. 1 mm tall; pseudopetioles ca. 1‒1.5 mm long, glabrous; blades lanceolate, 4–8 × 0.8–1.5 cm, papery, shallowly wavy when dry, glabrous, glaucous abaxially, base widely cuneate, apex acute, margins serrulate, longitudinal secondary veins 3 or 4 pairs, transverse veins inconspicuous. Inflorescence unknown.

Phenology. New shoots produced during June to July.

Distribution and habitat. This new species is only found in Tongzi County, north Guizhou, China. It occurs on the mountain top and grows at an altitude of 1790–1795 m, together with other taxa including Chimonobambusa utilis (Keng) Keng.f. , Rubus spp. and Dendropanax spp. etc.

Etymology. The specific epithet refers to the county in which the bamboo grows. The Chinese name is given as "ffiḢṮƜḦ"; Tóngzǐ Yù Shān Zhú (Chinese Pin-Yin transliteration).

Vernacular name. Jiàn Zhú (Chinese Pin-Yin transliteration); AEḦ(Chinese name).

Similar species and notes. Yushania tongziensis obviously belongs to Yushania sect. Brevipaniculatae which is characterized by usually more than 3 branches at mid-culm nodes, deciduous culm sheaths and reflexed blades of culm leaves. It is similar to Y. panxianensis T.P. Yi et J.J. Shi. The morphological comparison between Y. tongziensis and its similar species is shown in Table 1 .

Up to now, there are 14 species of Yushania founded in Guizhou, of which five species belong to sect. Brevipaniculatae .

Figures

FIGURE 1. Holotype of Yushania tongziensis N.H. Xia, Y.Y. Zhang & G. Xie. (IBSC0889717). Photo by Xing Li.

FIGURE 2. Yushania tongziensis N.H. Xia, Y.Y. Zhang et G. Xie. A: habitat; B & C: portion of young culm, showing the culm leaf and powder; D: Culm bud; E: portion of culm, showing branches; F & G: foliage leaves, showing leafy branch and serrulate margins of leaf blade; H: portion of foliage leaf sheath, showing oral setae; I: rhizome; J: portion of culm, showing culm thickness and lamellar pith. Photo by You-yuan Zhang.

FIGURE 3. Yushania tongziensis N.H. Xia, Y.Y. Zhang et G. Xie. A: rhizome; B: portion of young culm, showing the culm leaf; C: branch bud; D: portion of culm, showing branch; E: Leafy branch; F: portion of foliage leaf sheath, showing oral setae; G: vertical section of culm, showing culm thickness and lamellar pith. Drawn by Bo-Qiang Zhang.