Dendrobium multilineatum Kerr

Averyanov, Leonid V., Ponert, Jan, Nguyen, Phi Tam, Duy, Nong Van, Khang, Nguyen Sinh & Nguyen, Van Canh, 2016, A survey of Dendrobium Sw. sect. Formosae (Benth. & Hook. f.) Hook. f. in Cambodia, Laos and Vietnam, Adansonia 38 (2), pp. 199-217 : 210

11. Dendrobium multilineatum Kerr

Journal of the Siam Society , Natural History supplement 9: 230 (1933) . — Seidenf., Opera Botanica 83: 112, fig. 69 (1985); 114: 212, fig. 135 (1992). — Newman et al., A Checklist for the Vascular Plants of Lao : 264 (2007) . — Schuiteman et al., Nordic Journal of Botany 26: 285 (2008). — Aver., Turczaninowia 16 (4): 34 (2013). TYPUS. — Laos. Central Laos, Phu Bia , c. 1900 m, 12.IV.1932 A. F.G . Kerr 0972 (holo-, K [ K000596875 ]; iso-, AMES, P [ P00408019 , P00408020 ]) .

HABITAT, PHENOLOGY AND CONSERVATION STATUS. — Epiphyte on tall trees in primary evergreen broad-leaved and mixed humid mountain forests on sandstone and granite, commonly on steep rocky slopes near mountain tops. 1300-1900 m. Fl. February-April. Rare, but locally common. Expected IUCN Red List status – EN. DISTRIBUTION. — Laos (Kham Mouan and Xaisomboun provinces). Endemic .

MATERIAL EXAMINED. — Laos. Kham Mouan, Bounlapha, Hinnam No Protected Area, LA-VN 256 ( CPC Herbarium, LE, NHOL, NUOL).

DESCRIPTION

Stems cylindric to narrowly fusiform, ascending to erect, (15)20-40(50) cm long, 0.5-1 cm in diameter, of many nodes, internodes 2-4 cm long. Leaves narrowly ovate to oblong lanceolate, 3-6(8) cm long, 0.8-1.8 cm wide. Inflorescences 1-3, each with 1-3 flowers; floral bracts ovate, acute, 8-12 mm long. Pedicel and ovary 1.8-2.5(3) cm long. Flowers white, widely opening, 4.5-5.5 cm across, disc with numerous red lines. Sepals subsimilar, triangular narrowly ovate, acute to acuminate, 2.5-3 cm long, 8-12 mm wide, slightly keeled abaxially. Petals rhombic broadly obovate, round and shortly apiculate at apex, 2.5-3 cm long, 1.5- 2.2 cm wide, twice broader than sepals. Mentum broadly conical, straight, as long as pedicel and ovary or little shorter, 1.5-2 cm long, 0.8-1 cm in diameter at the base. Lip obovate rhombic, indistinctly 3-lobed; 3-3.5(4) cm long, 2.5-3(3.5) cm wide, slightly undulate along margin; side lobes half circular, erect; median lobe half circular to broadly ovate, broadening to base, at apex shallowly emarginate and shortly apiculate; disc and side lobes with 7-13 low red sub-parallel keels running along veins. Column white, 5-7 mm tall, 2.5- 3 mm wide; anther cap white, at front almost flat, apically truncate ( Figs 2H ; 3A ).

REMARKS

This species seems closely related to D. wattii , from which it differs in a indistinctly 3-lobed lip and the numerous low parallel bright red keels on the disc (in original description – “Flowers white with reddish brown markings on lip…”).

The species was observed in Kham Mouan province of eastern Laos very near to Vietnamese border hence it may be found also on the territory of Vietnam. A published record of this species in Vietnam from Hon Ba mountain in Khanh Hoa province ( Choudhary et al. 2012: 225) belongs to D. trankimianum , which is a rather common epiphyte on large trees in mountain forest on the peaks of Hon Ba mountain.

Figures

FIG. 2. — A, Dendrobium kontumense Gagnep.(L.Averyanov s.n., X.2005);B, D. roseiodorum Sathap.,T.Yukawa & Seelanan (L.Averyanov s.n., X.2005);C, D, D. daklakense Tich,Schuit. & J.J.Verm.; C, Vo Van Cong, s.n., XI.2015; D, V.Q.Binh & L.Averyanov, s.n., 7.XI.2014; E, D. infundibulum Lindl. (L.Averyanov s.n., Thailand, Chiangmai, 2002); F, G, D. wattii (Hook.f.) Rchb.f.; F, L.Averyanov s.n., XI.2013; G, HAL 8630; H, D. multilineatum Kerr (LA-VN 256). Photos: A-G, L. Averyanov; H, N. S. Khang.

FIG. 3. — A, Dendrobium multilineatum Kerr (LA-VN 256); B-D, Dendrobium williamsonii Day & Rchb.f. (CPC 24290); E, F, D. cariniferum: Rchb.f.; E, VH 2256a; F, HLF 5500a; G, H, D. longicornu Lindl. (CPC 5378); I, D. chapaense Aver. (N.A.Duc et al., HL 131). Photos: A, N. S. Khang; B-H, L. Averyanov; I, N. A. Duc.