Dendrobium longipedicellatum 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): 102, fig. 21-23
Type: Leiden cult. 20080720 (de Vogel & Raka) (holo L).
Roots filiform, flexuose, glabrous. Rhizome short, creeping. Pseudobulbs close together, cylindrical, 6-angled, 2–4 by 1–1.5 cm, distinctly narrower to the apex. Leaves oblong, c. 3–4.5 × 1–1.5 cm, index c. 3; base narrowed; apex acute. Inflorescences in fascicles of 2–5 on the pseudobulb, 5–7 cm long; peduncle 1.7–2.3 cm long, longer than the spathe; spathe 0.5–0.9 cm long. Pedicel and ovary c. 3.5–4.7 cm long; ovary in section triangular, with 3 low inconspicuous ribs, pale yellow. Flower not opening wide, c. 2 cm across. Median sepal narrowly triangular, c. 2.6 by 0.38 cm, not upright; top half semi-tubular; apex acute. Lateral sepals obliquely narrowly triangular, widest at the base, c. 2.6 by 0.7 cm, not spreading; top half semi-tubular; apex acute; mentum conical, obtuse, c. 0.55 cm long. Petals narrowly linear-lanceolate, c. 2.4 by 0.12 cm, not spreading; median third semi- tubular; top third swollen; apex acute. Lip distinctly shorter than the sepals, when flattened oblong-ligulate, c. 1 cm long; 5-keeled; hypochile rather narrowly attached, when flattened widest near its top, c. 0.5 by 0.5 cm; lateral lobes at the back forming a small rounded auricle, in front not pronounced; keels 2, subparallel, rather swollen, in top 1/4 of the hypochile converging till touching, continuing as lower, thinner, plate-like, undulating keels (c. 4 curves) up to the top 1/4 of the epichile; epichile semi-elliptic, c. 0.5 by 0. 5 cm; top rather broad acute; median from base till top 1/5 with plate-like, hardly undulating third keel; lateral of each of these keels with a low, laterally slanting keel with a rather regularly incised crest. Column c. 0.15 by 0.2 cm, c. 0.25 cm wide; clinandrium 3-lobulate, the lateral lobes 3-denticulate, the median lobule a subulate cusp; column-foot gradually curved, in natural position c. cm long. Anther semi-elliptic-cucullate, in front truncate, glabrous
(After De Vogel in De Vogel, Vugt & Hoogendijk 2018)