Dendrocalamus velutinus N.-H. Xia, V. T. Nguyen & V. D. Vu

Nguyen, Van Tho, Le, Viet Lam, Vu, Van Dung & Xia, Nian-He, 2012, Dendrocalamus velutinus N. - H. Xia, V. T. Nguyen & V. D. Vu (Poaceae), a new species from Vietnam, Candollea 67 (2), pp. 255-259 : 256-258

Dendrocalamus velutinus N.-H. Xia, V. T. Nguyen & V. D. Vu , spec. nova ( Fig. 1 , 2).

Typus: VIETNAM. Hanoicity: Bavi district, Bavi national park , Bavi mountain , 198 m, 21°05’47’’N 105°21’58”E, 26. I.2011, Van Tho Nguyen NVT260 (holo-: FSIV; iso-: IBSC!, FSIV-CH!).

Species nova D. calostachyo affinis, sed vaginorum ligulis 8-10mm longis, fimbriatis, ligulisfoliorum truncatis, intergris, glabris, palea 7.4-9.8 mmlonga, apice truncata aut obtusa, 2-nervibus inter et extra carinam, foliismajoribus differt.

Arborescent bamboo, rhizomes pachymorph, short-necked. Culms erect, 14-16 m tall, 10-15 cm in diameter, apex pendulous; internodes terete, 27-37 cm long, wall 3 cm thick, covered with tawny-coloured velvet, remaining with age, intranode with a 7-8 mm high ring of tawny-coloured velvet, infranode with a 4 mm high ring of tawny-coloured velvets. Branches several at each node, central dominant, branching from 1 st -2 nd node. Culm sheaths deciduous, (23-) 42-56 cm long and (19-) 33-54 cm wide, abaxially brown sericeous, margins deciduously white pilose; apex narrow, lightly concave; oral setae absent; auricles absent; ligule irregularly fimbriate, 8-10 mm long; blade erect, 3.8-7 9.5-12 cm, adaxially brown sericeous, abaxially glabrous, both sides with clearly longitudinal ribs, margins setose, apex gradually acute. Leaves of ultimate branch (7-)8-9(-11), sheaths glabrous; auricles absent; ligule truncate, c. 2 mm high, entire, glabrous; leaf blade broadly oblong-lanceolate, leaf size various, big ones 42-52.5

10-11 cm, small ones 27-34 3.1-6.2 cm, apex acute, base nearly rounded, abaxial glabrous, adaxial rough, pedicel 6-7 c. 2 mm, secondary veins (10-)13-15(-18) each side of midrib. Inflorescence consisting of a large compound panicle with branchlets bearing spikelets, flowering branch pendulous, leafless, with 5-8(-15) clustered pseudospikelets at each node; pseudospikelet fusiform, purple green, apex slightly obtuse, 11-13 4.5-5.5 mm, sterile spikelet 7-8 2-3 mm; prophyll 1-keeled, scalene triangle, 5.6-5.7 3.8-4.1 mm, dorsal surface pubescent, margin ciliate, apex blunt; florets 4-5, all fertile, opening when mature; rachilla-internodes very short and not disarticulating. Glumes 1 or 2, 7.1-7.5 5.3-6.3 mm, puberulent, apex acute, margins ciliate, many-veined; lemma narrowly lanceolate, 11.2-12.6 5.8-7.7 mm, abaxially thinly puberulent, apex acute, margin pilose, many-veined; palea oblong-lanceolate, 7.4-9.8 3.4-3.9 mm, 2-keeled, abaxially pubescent, 5-veined between and 2-veined on either side of keels, apex obtuse or truncate, apex of uppermost palea usually acute, margins and keels pilose; lodicules absent. Anthers yellow, 6.6-6.9 mm long, exserted, apex acute, with few white hairs; filaments distinct, separate; stamen 6. Ovary ovoid, densely hairy; pistil 8.1-12.1 mm long. stigma 1, hairless.

Vernacular name. – Buong moc.

Flowering period. – December to January, fruit unknown.

Notes. – Dendrocalamus velutinus bears a close resemblance to D. calostachyus (Kurz) Kurz in general appearance, but differs in its culm sheath ligule 8-10 mm long, irregularly fimbriate, leaf ligule c. 2 mm high, entire and truncate, palea 7.4-9.8 mm long 2-veined between keel and edge, apex obtuse or truncate, and larger leaves. The different characters are summarized in Table 1 .

Distribution and habitat.– The species grows in secondary broadleaf forest between 100 and 600 m altitude on Bavi Mountain of Bavi National Park, Bavi District, Ha Noi city. It is also cultivated in Tan Lac, Luong Son, Ky Son Districts, Hoa Binh province and Cau Hai Bamboo Garden, Chan Mong commune, Doan Hung district, Phu Tho province.

Local uses and etymology. – This species is economically valuable to the local people. The sweet, delicious bamboo shoots are used for food. The culms are used for house construction and general household use, raw material for paper pulp and floorboard industries. The specific epithet refers to the indument character on the culm internodes.

Additional specimens examined. – VIETNAM. Hanoicity: Bavi district, Bavi national park , Bavi mountain , 198 m, 21°05’47’’N 105°21’58”E, 19.IX.2010, Van Tho Nguyen NVT224 ( FSIV, IBSC, FSIV-CH) . Hoa Binh: Luong Son, Lam Son , 67 m, 21°54.264’N 105°28.130’E, 1.IX.2010, Van Tho Nguyen NVT156 ( FSIV, IBSC, FSIV-CH) ; Tan Lac, Phong Phu , 70 m, 1.IX.2010, Van Tho Nguyen NVT159 ( FSIV, IBSC, FSIV-CH) ; Ky Son, Yen Quang , 109 m, 20°39.222’N 105°17.045’E, 21.IX.2010, Van Tho Nguyen NVT245 ( FSIV, IBSC, FSIV-CH) . Phu Tho: Doan Hung, Cau Hai bamboo garden , 49 m, 20°31.683’N 105°11.817’E, 5.VIII.2010, Van Tho Nguyen NVT026 ( FSIV, IBSC, FSIV-CH) .

Figures

Fig 1. – Dendrocalamus velutinus N.-H. Xia, V. T. Nguyen & V. D. Vu. A. Culm and dormant bud; B. Culm sheath (abaxial view); C. Culm sheath (adaxial view); D. Leaf; E. Leaf ligule; F. Flowering branch; G. Pseudospikelet; H. Prophyll; I. Glume; J. Lemma; K. Palea; L. Pistil; M. Anther. [A-C: V. T. Nguyen NVT224, FSIV; D-M: V. T. Nguyen NVT260, FSIV] [Drawn by V. T. Nguyen]