Dendrobium tetrapterum M.Z.Huang, C.Y.Wei & M.H.Li

Wei, Chun-Yi, Li, Ru-Yi, Wu, Yu-Wei, Huang, Ming-Zhong & Li, Ming-He, 2024, Dendrobium tetrapterum, a cryptic species in the D. lindleyi alliance (Orchidaceae; Dendrobiinae): evidence from morphological and molecular data, Phytotaxa 655 (2), pp. 209-218 : 212-213

Dendrobium tetrapterum M.Z.Huang, C.Y.Wei & M.H.Li , sp. nov. (四OiHDZ; Figs 2–5 )

Type:— CHINA. Hainan: epiphytic on tree trunk in evergreen broad-leaved and sunny open forest, elev. ca. 300 m, 14 May 2014 Huang 130322001 (holotype: ATCH!).

Dendrobium tetrapterum is similar to D. lindleyi and D. jenkinsii , but can easily be distinguished by the petals without (vs. with) claw, slit (vs. entire) transverse septum at lip base, anther cap with (vs. without) indentation on each side and rhombic (vs. pentagonal– octagonal or oblong) pseudobulb cross-section.

Epiphytic herbs with creeping rhizomes, slender, 2–3 mm in diam, branched. Pseudobulbs prostrate, crowded, fusiform, compressed, 1.0–5.0 × 0.5–1.5 cm, with 2–5 nodes, internodes 1.0–2.0 cm, with 4 ribs, pale yellowish brown and glossy when dry, with white sheaths. Leaf usually solitary, oblong, 3.0–8.0 × 0.6–3.0 cm, base contracted, not sheathing, apex obtuse and emarginate. Inflorescence subterminal, to 27 cm, much longer than leaves, laxly several to up to 15- flowered; floral bracts narrowly ovate-triangular, ca. 2 mm long. Pedicel and ovary yellowish green, tinged with pale purple, 2.8–3.2 cm long. Flowers spreading, orange-yellow. Dorsal sepal ovate-lanceolate, 13.0 × 8.0 mm, subobtuse; lateral sepals nearly equal to dorsal sepal, 15.0 × 9.0 mm. Petals broadly elliptic, 19.0 × 12.0 mm, obtusely round. Lip transversely oblong or subreniform, usually 21.0 × 26.0 mm, entire, often emarginate; disk densely pubescent below middle, below middle contracted into a claw with the sides clasping column; near base with a transverse septum, split into two lobes. Column 3.5 mm long, 2.5 mm in diameter, column foot 4.0 mm long, at the base with an oval concavity; anther cap subglobose, glabrous, with an indentation on each side, pollinia naked, terete, 4 in two pairs.

Phenology:— Flowering April, May.

Distribution:— China (Guangdong, Guangxi, Hainan, SW Guizhou, Yunnan), Vietnam (Cao Bang, Bac Can, Thai Nguyen, Ninh Binh, Quang Ninh) and Thailand (Chiang Mai).

Habitat and ecology: Epiphytic, below 1800 m elevation.

Other specimens studied:— THAILAND. Chiang Mai: Doi Suthep , 800–1200 m, Jun 1905, Hosseus 818 ( MO168775 ) . VIETNAM. Cao Bang: Thach An district, municipality Thuy Hung, vicinities of Na Lit village (22°30′N, 106°27′E), 500–550 m, 4 Dec 1998, CBL 892 ( LE01077119 ) ; Thach An district, municipality Duc Xuan, ( N22 °21′’ E 106 °27′), 2 Dec 1998, CBL 808 ( LE01066396 ). Bac Can : Na Ri district , Kim Hy municipality, vicinities of Lung Hin Con village (22°17′N, 106°03′E), 27 km to 55° of Bac Kan city, 800 m, 19 Oct 1999, NTH 3673 ( LE01066399 ) ; Cho Don district, Ban Thi Municipality, Cho Dien village (22°14′28″N, 105°29′50″E), 250-350 m, 26 Dec 2002, HLF 849 ( LE01077112 ). Thai Nguyen: Dong Hy district , Tan Long Municipality, vicinity of Mo Ba Village (20°46′26″N, 105°52′25″E), 400–550 m, 14 Mar 2001, HAL 7 ( MO5686816 ). Ninh Binh: Cuc Phuong National Park (105°43.08′N, 20°14.22′E), 20 Dec 1933, CP146 ( L0402526 ). Quang Ninh: Dam-ha district , Sai Wong Mo Shan (Sai Vong Mo Leng) Lomg Ngong Village , 18 Sep 1940, Tsang 30162 ( AMES02156601 ) ; Ching Mai district, Ku Tang Village, Pak Shik Ling and vicinity, 31 Mar 1933, Lei 496 ( AMES02156889 ) ; Yaichow , 1800 ft., May-Jul 1933, How 70525 ( P00407945 ) . CHINA. Hainan: Apr 1932, Liang 61648 ( IBSC0626361 ) ; Apr 1932, Gao 52251 ( IBK00145549 , IBSC0626365 , PE00851167 ) ; May 1932, McClure 20080 ( IBSC0626360 , PE00293829 ) ; Apr 1932, Mar 1933, Lei 496 ( IBSC0626359 , PE00293830 ) ; 0–1800 m, Apr 1933, Hou 70525 ( SN002661 , IBK00145547 , IBSC0626362 , PE00293828 ) ; Apr 1936, Liu 26046 ( IBK00145546 , IBSC0626364 , PE00293826 ), Apr 1998, Chen 699 ( IBSC0745773 ) ; 14 May 2014, MHLi or139 (FJFCor139). Guangxi: no precise date, Nong-gang Comprehensive Expedition Team 10949 ( IBK00145541 ) ; no collector, 1036 ( PE00293832 ) & 96394 ( IBK00145542 ) ; Beijing-dui Team 893060 ( PE01997725 ) ; Jun 1935, Gao 55358 ( IBK00145534 ) ; Jul 1936, Liang 67911 ( IBK00145531 ) & 67932 ( IBK00145536 ) ; 0–1000 m, Jul 1936, Su 67911 ( IBSC0626367 ) ; Soo 67932 ( PE00293833 ) ; Jun 1937, Liang 69407 ( IBK00145535 ) ; May 1956, Wei 64 ( IBK00145532 ) ; Jul 1956, Shu A61245 ( IBK00145544 , PE00293837 ) ; Jul 1958, Li 600971 ( IBK00145545 , PE00293835 ) ; 510 m, Jan 1959, Li 602805 ( IBK00145533 , PE00293836 ) ; May 1959, Li 403810 ( IBK00145543 ) ; Oct 1959, Zhong A63761 ( IBK00145537 ) ; Nov 1981, Da-yao-shan Comprehensive Expedition Team 13191 ( IBK00196191 ) ; Apr 1998, Chen 699 ( IBSC0626366 ) ; Jun 2001, HK kadoorie PT 790 ( PE01997724 ) ; Jun 2007, Lu, Mo, Xue & Li 16838 ( GXMG0035395 ) ; 700 m, Jun 2010, Xu & Jiang 10746 ( IBK00281750 ) ; 154 m, Sep 2012, Lu, Nong, Huang et al 451422120907032LY ( GXMG0102359 ) ; 412 m, Jul 2013, He & Yang YangXF0322 ( KUN1393816 ). Guangdong province : no precise data, 61648 ( PE00293827 ) ; Aug 1931, Gao 51730 ( IBSC0626338 ) ; Jun 1932, Huang 32345 ( IBSC0626336 ) ; Jun 1933, Zuo 22777 ( IBSC0626337 ) ; May 1943, Chen 11886 ( IBSC0626335 ) ; 90 m, Jun 1958, Huang 110488 ( PE00293831 ) ; May 1972, Luo 667 ( IBSC0626341 ) ; Aug 1972, Luo 1212 ( IBSC0626340 ) ; Sep 1978, Yue 78 6193 ( IBSC0626334 ). Yunnan province : 1000 m, Nov 1980, Ji 89 ( PE 00850236 ) ; Jun 1981, Ji 114 ( PE00850234 ) ; Mar 1983, Chen & Ji 1 ( PE00850231 ) & 22 ( PE00850228 ) ; Apr 1983, Ji 129 ( PE00850235 ) ; 1600 m, Jul 1985, Ji 258 ( PE00850227 ). Guizhou province : Oct 1958, Cao 1011 ( PE00293824 ) .

Figures

FIGURE 2. Morphological comparison of Dendrobium lindleyi (I), D tetrapterum (II) and D. jenkinsii (III). A. Pseudobulb and leaf. B. Cross-section of the middle of pseudobulb. 1-3 samples from distinct members of the same species.

FIGURE 3. Floral comparison of Dendrobium lindleyi (I), D. tetrapterum (II) and D. jenkinsii (III, provided by Yu Zhang & Ze Zhang).A. Flower. B. Lip. C. Lip base (enlarged view of dotted boxes of B). D. Dorsal sepal. E. Lateral sepals. F. Petals. G. Column foot. H. Stelidia (enlarged view of dotted boxes of G). I. Anther. J. Anther cap.

FIGURE 4. Line drawing of Dendrobium tetrapterum. A. Flowering plant. B. Flower. C. Dorsal sepal. D. Petal. E. Lateral sepal. F. Lip. G. Lip base (enlarged view of dotted box of F). H. Anther cap and anther. I. Column and column foot. J. Stelidia (enlarged view of dotted box of I). K. Cross section of pseudobulbs in extreme cases.

FIGURE 5. Dendrobium tetrapterum. A. Habitat. B. Inflorescence. C. Flowering plants and leaves. D. Non-flowering plant.