Schizostachyum longinternodium N. H. Xia, R. S. Lin & C. H. Zheng, 2014

Zheng, Chaohan, Lin, Rushun, Ni, Jingbo & Xia, Nianhe, 2014, Schizostachyum longinternodium (Poaceae: Bambusoideae), a new species from Yunnan, China, Phytotaxa 184 (3), pp. 155-159 : 158

Schizostachyum longinternodium N. H. Xia, R. S. Lin & C. H. Zheng sp. nov. ( Figs 1 & 2 )

Type:— CHINA. Guangdong: South China Botanical Garden (cultivated, introduced from 21°56´N; 101°14´E, Menglun, Xishuangbanna, Yunnan) , 5 May 2010, Zheng Chaohan 024 (holotype IBSC!, isotype KUN!) .

Diagnosis: — Schizostachyum longinternodium sp. nov. is similar to S. funghomii McClure , but differs by its slightly drooping apex, shorter culm sheaths (less than 1/3 of the internodes) with protuberances on culm sheaths shoulders, persistent oral setae on the leaf sheaths, a solitary floret in every spikelet, and connate filaments. ( Table 1)

Rhizomes pachymorph. Culm erect, 8–12 m tall, 3–6 cm diam., apically slightly drooping. Internodes 56–86 cm long, terete, scabrous, siliceous, white powdery below nodes, white strigose; walls ca. 2 mm thick. Nodal ridge not prominent, sheath scars prominent. Branching from the 6th–9th node upwards; branches many, subequal, 45–90 cm long. Culm sheaths tardily deciduous, thickly papery, brittle, lower ones less than 1/3 the length of internodes, ribbedstriate when dry, siliceous, white strigose, with protuberances on its shoulders, the margin with cilia 1 mm long, the apex truncate; auricles inconspicuous, the oral setae numerous, 3–8 mm long, hispidulous at base; ligule truncate or not, 1 mm tall, the margin lobed; blade reflexed, linear-lanceolate, less than 1/3 the length of the sheath at lower nodes, abaxially glabrous, adaxially densely hispid, the apex acuminate. Leaves 5–9 per ultimate branch; sheath up to 12 cm long, initially hispid, usually siliceous, margin ciliate; auricles inconspicuous, oral setae numerous, 3–5 mm; ligule ca. 1 mm, margin lobed; petiole 4–6 mm long; blades oblong-lanceolate to ovate-lanceolate, 26–42 cm long, 4–6.5 cm wide, margin on both sides denticulate, adaxially glabrous, abaxially densely pubescent, base rounded, apex acuminate. Inflorescence branches ca. 30 cm long, clustered at nodes of culms and branches, occasionally terminal to leafy branches. Pseudospikelets fusiform, green infused with purple, the prophylls lanceolate, asymmetrical, ca. 5 mm long, papery, apex acuminate, keels 2, ciliate, converging at the tip; bracts 1 to several, oblong, 1–1.3 cm long, papery, many-veined, the apex obtuse to acute and mucronate, the mucro less than 1 mm long; floret solitary, 3 cm long; rachilla disarticulating, internode ca. 3 mm long; terminal rachilla prolongation 1.5–1.8 cm long, slender, embedded in the groove between the 2 keels of the palea; the glumes absent; the lemma oblong-lanceolate, papery, 1.5 cm long, densely white hispidulous, many-veined, apex acute and mucronate, the mucro ca. 1 mm long; palea 2.5–3 cm long, papery, nearly glabrous, apically bifid; lodicules absent; filaments ca. 1.8 cm long, connate and tubular; anthers 6, purple, ca. 1.1 cm long; ovary narrowly ovoid, glabrous, not distinctly separated from the style; style pale-yellow; stigmas 3, purple, plumose. Caryopsis fusiform, ca. 2 cm long.

Distribution, habitat and phenology: — Schizostachyum longinternodium is distributed in south and southeast Yunnan, China. It grows in forest, in gullies or along rivers, 550–600 m elevation.A plant was introduced to Guangzhou and flowered from March to October, 2010, and the whole clump died. In the following year, the seeds germinated and the seedlings developed the same characters as the parent.

Local use: —It is suitable for weaving utensils because of its long internodes.

Etymology: —The specific epithet refers to the long internodes.

Figures

FIGURE 1. Schizostachyum longinternodium sp. nov. (drawn by Dinghan Cui and Chaohan Zheng based on the type specimen Chaohan Zheng 024, IBSC.) A. leafy and flowering branches. B. culm leaf sheath on part of culm. C. part of the culm. D. branch complement of subequal branches. E. two pseudospikelets. F. two prophylls. G. lemma (right) and palea with rachilla prolongation (left). H. rachilla internode. I. stamens. J. pistil. K. pubescence on abaxial surface of foliage leaf.

FIGURE 2. Schizostachyum longinternodium sp. nov.(Guangzhou, Apr. 2010. Photo by Chaohan Zheng) A. sheath on part of culm. B. flowering branches. C. pseudospikelet. D. stamens and ovary. E. prophyll.