Species Information - Dendrobium senggiense

Dendrobium senggiense de Vogel in De Vogel, E.F., van Vugt, R. & Hoogenfdijk, E.A.H., Dendrobium section Diplocaulobium subsection Goniobulbon (Orchidaceae) 1: The Species with 4 or 5 Keels on the Epichile, Malesian Orchid Journal Vol. 22 (2018): 110, fig. 32-34

Type: Keerom cult. 106 (de Vogel & Suhartawan) (holotype Yayasan Pendidikan Alam Papua, Keerom, temporarily deposited at Universitas Cenderawasih, Jayapura)

Synonyms:

Roots filiform, flexuose, thin, c. 0.1 cm thick. Rhizome creeping. Pseudobulbs very close together, partly overlapping and appressed to the base of the next pseudobulb, conspicuously dorso-ventrally flattened, elliptic in outline, up to 0.8 by 0.8 by c. 0.3 cm; with a low median ridge; often long covered by a dried, membranous scale leaf which does not overtop the pseudobulb. Leaves ovate to elliptic, 1.2–1.5 by 0.7–0.9 cm, index 1.6–1.7, thick coriaceous, stiff; apex oblique, relatively deeply notched, with broadly acute, slightly unequal lobules. Inflorescences 1 per pseudobulb, arising in succession from the pseudobulb, c. 1.5 cm long; peduncle c. 0.5 cm long, about as long as the c. 0.5 cm long spathe. Flower 1.4–1.6 cm high, opening widely; sepals & petals creamy-white with hyaline nerves, towards the base pale yellow; lip creamy white, lateral lobes with a narrow dull purple margin, keels pale yellow; column creamy white, stigma and anther creamy white or greenish yellow. Pedicel and ovary c. 1 cm long, terete, the ovary slightly grooved. Flower widely opening. Median sepal very narrowly triangular, 1.3 by c. 0.3 cm, recurved; semi-tubular; apex acute, not thickened. Lateral sepals strongly curved, falcate, obliquely triangular, when not stretched c. 1 by c. 0.55 cm when flattened; top half semi-tubular; apex acute, not thickened; mentum conical, obtuse, c. 0.6 cm long. Petals linear-triangular, c. 1 by 0.1 cm; semi-tubular in upper 2/3; apex acute, not thickened. Lip very slender, curved at the top, c. 1.05 cm long; keels 5, glabrous (magn. 25x); hypochile when flattened long rectangular, c. 0.5 by 0.3 cm, narrower at the base and there broadly attached over 0.1 cm, leaving minute lateral auricles; lateral lobes in lateral view in front truncate to broadly rounded and receding; main keels 2, the median keel insignificant, somewhat apart, parallel and straight, the lateral keels distinctly swollen; in top 1/4 of the hypochile converging and almost touching; median nerve somewhat swollen; epichile when flattened narrowly ovate, c. 0.55–0.6 × 0.25 cm; top acuminate; margin irregular, undulating; median keel from base to almost the top of the epichile, only slightly undulating; inner lateral keels plate-like and only slightly undulating, c. 0.12 cm shorter than the median keel; outer lateral keels short, low, less than 1/4 of the length of the epichile. Column c. 0.2 by 0.13 cm, c. 0.2 cm wide; clinandrium 3-lobulate, the lateral lobules broadly triangular, the median one subulate, 0.05 cm long; column-foot gently curved, in natural position c. 0.5 cm long. Anther hood-shaped, c. 0.12 by 0.1 cm; apex projecting, broadly triangular.
(After De Vogel in De Vogel, Vugt & Hoogendijk 2018)

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