Dendrocalamus menghanensis P.Y.Wang & D.Z.Li, sp. nov. "勐罕龙竹" (Meng Han Long Zhu)

Wang, Ping-Yuan & Li, De-Zhu, 2019, Dendrocalamus menghanensis (Poaceae, Bambusoideae), a new woody bamboo from Yunnan, China, PhytoKeys 130, pp. 143-150 : 143

Dendrocalamus menghanensis P.Y.Wang & D.Z.Li, sp. nov. "勐罕龙竹" (Meng Han Long Zhu) Figures 1 , 2

Type.

CHINA. Yunnan: Xishuangbanna, Menglun, 21°55.949'N, 101°15.139'E, 570 m alt., 18 November, 2010, P.Y. Wang C130022 (holotype: HITBC!; isotype: KUN!).

Diagnosis.

Dendrocalamus menghanensis is morphologically similar to D. semiscandens and D. birmanicus , but can be easily distinguished from them by having a reflexed culm sheath blade, 10 mm high culm sheath ligule, 1 mm high leaf sheath ligule, 4 florets and 1 glume.

Description.

Arborescent bamboo, perennials; rhizomes pachymorph, short necked. Culms apically pendulous, 8-12 m tall, 4-8 cm in diam.; culms terete, with a ring of white tomenta below sheath scars, internodes 20-40 cm long, wall 1-3.5 cm thick and almost solid at the base of culms; culm surface initially densely covered with white hairs and becoming glabrous later; culm sheaths deciduous, thickly leathery, 1/2 as long as the internodes, covered with dense brownish-black hairs, pale green initially, later becoming yellowish-brown with age; blades lanceolate, reflexed; auricles small inconspicuously lobed, oral setae absent; ligules ca. 10 mm high, dentate. Branching from lower nodes ca. 0.5-1.0 m above ground, branches several, usually subequal, sometimes 1 dominant; ultimate branchlets with 10-16 leaves, usually 12 leaves. Foliage leaves lanceolate, 11-30(-35) cm × 2-4.5(-6) cm, adaxial surface green and glabrous, abaxial surface pale green and pubescent, margins serrulate, secondary veins 7-11 pairs, usually 10 pairs, petioles 2-5 mm; leaf sheaths initially white hairy and later glabrous; auricles inconspicuous, ligules ca. 1 mm high, entire. Flowering branches pendulous, leafless, with clusters of 3 to 15(-60) pseudo-spikelets at each node; clusters 1-3.5 cm in diam.; pseudo-spikelets ovate-lanceolate, pale green, apically acute and light purple, 12-16 × 3-4 mm; fertile florets usually 4 per pseudo-spikelet; glumes 1, broadly ovate, 5-7 × 4-6 mm, margins ciliate at upper half; lemma ovate, 8-12 × 4-7 mm, pubescent, many-veined, apex mucronate, margins ciliate; palea oblanceolate, 2-keeled, 7-11 × 1-2 mm, keels and margins long ciliate; lodicules absent; stamens 6, ca. 6 mm long, ovary ovoid, pistil ca. 16 mm long, anthers yellow, filaments free, ca. 14 mm long; stigma 1, purple, plumose. Fruit unknown.

Distribution.

Dendrocalamus menghangensis is only known from Menghan Township, Jinghong, Yunnan, China.

Conservation status.

As a great many forests have been destroyed by local people in the last 30 years, we did not find the new species at the locality where it was introduced. Further investigation is required to find more distribution localities and determine the conservation status of the new species. At present, we consider it as DD (Deficient Data) according to the IUCN parameters ( IUCN 2012).

Etymology.

The specific epithet refers to the original place of the new species, i.e. Menghan Town, Xishuangbanna, south Yunnan, China.

Phenology.

Shooting from July to October and flowering from December to May of the next year.

Additional specimens examined (paratype).

CHINA. Yunnan, Xishuangbanna, Menglun, 21°55.949'N, 101°15.139'E, 570 m alt., 7 December, 2010, P.Y. Wang C130051 (paratype: HITBC!, KUN!)

Figures

Figure 1. Dendrocalamus menghanensis P. Y. Wang & D. Z. Li. A Culm sheath (abaxial view) B ultimate branchlet with leaves C portion of young culm with culm sheath D portion of flowering branch E pseudo-spikelet F pistil G stamen H glume I lemma J Palea. Drawn from the holotype.

Figure 2. Dendrocalamus menghanensis P. Y. Wang & D. Z. Li. A Clump B portion of young culm with culm sheath C new shoot D flowering branches E glume F lemma G palea H floret I pistil J ovary.