Dendrocalamus multiflosculus H.N.Nguyen, N.H.Xia & V.T.Nguyen, 2013

2. Dendrocalamus multiflosculus H.N.Nguyen, N.H.Xia & V.T.Nguyen View in CoL , sp. nov. — Fig. 3 View Fig , 4 View Fig ; Map 1 View Map 1

Species nova D. calostachyo (Kurz) Kurz affinis,sed pseudospiculis flosculas maturas usque 9–10 ferentibus, paleis 12–13.8 mm longis, 2-nervatis extra carinas,antheris 8–9.2 mm longis, culmorum vaginis dorsaliter dense brun- neis tomentosis ad inferior 1/3 partem differt. — Typus: Van Tho Nguyen NVT 139 (holo FSIV; iso FSIV, FSIV-CH, IBSC), Vietnam, Son La, Mai Son, Chieng Ban, cultivated in household garden, N21°13.436', E103°57.397', alt. 768 m asl, 22 Aug. 2010.

Etymology. The specific epithet refers to the many perfect florets.

Arborescent bamboo, rhizomes pachymorph, short-necked. Culms erect, 20–24 m tall, 12–17 cm diam, apex erect or slightly nodding; internode terete, (15–)23–30(–39) cm long, wall 1.8–2 cm thick, initially densely brown tomentose and white powdery, becoming glabrous with age, both intranode and infranode glabrous, dormant bud triangular, basal internodes normal. Branches several, central dominant, branching from 32–34 node up, c. 12 m above ground. Culm sheaths caducous, leathery, lower third densely brown tomentose, entirely covered with thinly white powder when young, becoming glabrous when old, margins glabrous; apex nearly rounded; auricles absent; ligule c. 4 mm high, serrulate; blade lanceolate, horizontal or nearly erect, c. 1/5 as long as sheath proper, adaxially setose, abaxially glabrous, base extended toward both sides and joined with auricles, margins setose, apex acuminate. Leaves (7–)8– 10(–11) per ultimate branch; sheath brown-hairy; auricles lacking; ligule truncate, c. 2 mm long, entire, glabrous; pedicel c. 6 by 3 mm, brown velvety at joint with sheath; leaf blade lanceolate, 36–43.6 by (4.8–) 7–9.2 cm, base cuneate, abaxially glabrous, adaxially rough, apex acuminate, secondary veins 13–14 pairs. Inflorescence iterauctant; flowering branches with leaves, pendulous, with (1–)5–7 clustered pseudospikelets at each node; pseudospikelet lanceolate, (12–)18–25 by 6–10 mm, purple-brown; prophyll triangular, 4.6–5.4 mm long, 1-keeled, margins and keel densely long-ciliate; florets 9–10, terminal floret perfect and each floret closed when mature; rachilla very short and not disarticulating. Glumes 5–6, 8.8–10.7 mm long, margin long-ciliate, many-veined; lemmas broadly ovate, 10.8–12.7 by 10.5–13.9 mm, apex blunt or truncate, abaxially covered with appressed bristles in the middle, margins ciliate, many-veined; palea narrowly lanceolate, 12.9–13.8 by 2.8–3.1 mm, 2-keeled, 4-veined between and 2-veined on either side of keels, abaxially densely pubescent, apex acute and sometimes bifid, apex of uppermost palea usually acute; lodicules absent. Anthers yellow, 8–9.2 mm long, exserted, apex acute, with several white hairs; filament free, c. 7 mm long; stamens 6. Ovary narrowly lanceolate, hairy, base with stalk c. 0.6–0.7 mm; stigma 1, hairless; pistil 14.7–17 mm long. Flowering observed in August, fruit unknown.

Distribution & Habitat — Currently unknown. This species is only seen in Ban Ang village, Chieng Ban commune, Mai Son district, Son La province.

Phenology — Dendrocalamus multiflosculus produces shoots from August to October.

Uses — Young shoots are used for food at the local.

Vernacular name — Pụa mốn.

Note — Dendrocalamus multiflosculus is like D. calostachyus in general appearance, but differs in its pseudospikelets bearing 9–10 florets, palea 12.9–13.8 mm long, 2-veined between keel and edge, anthers 8–9.2 mm long, culm sheath densely brown tomentose on the lower 1/3 part. The distinguishing characters are summed up in Table 2.