Prev Taxon: Genus Dendrobium section Fugacia
Current Genus: Genus Dendrobium Section Grastidium
Next Taxon: Genus Dendrobium section Herpetophytum
Dendrobium polyrhopalon
Dendrobium polyrhopalon Ormerod, Checkl. Papuasian Orch. (2017) 243, 487 (fig.).
Type: Brass 2720/ (holo AMES; iso L).
Synonyms:
Epiphyts. Roots terete, to 0.2 cm thick. Rhizome not seen. Stem slender, transversely elliptic in section, sublaxly leafed, c. 38.5 by 0.18 cm, 0.10 cm thick. Leaves lanceolate, 5.9-7.5 by 1.2-1.35 cm; leaf sheaths tubular, striate, minutely verrucose, 1.2-2.1 cm long, at the apex with a triangular, 0.08-0.1 cm long lobe with an acute apex; apex with 2 minute obtuse lobes differing 0.05-0.1 cm in length. Inflorescence 2-flowered; peduncle 0.5 cm long; basal inflorescence scales: 1st transversely oblong, 0.1-0.15 by 0.2-0.3 cm, 2nd semi-elliptic, 0.2-0.3 by 0.25-0.3 cm, with obtuse apex; 3rd oblong, thin, papery, 0.22 by 0.08-0.1 cm, with truncate apex. Pedicel and ovary terete, club-shaped,1.5-1.6 cm long. Median sepal linear-lanceolate, 3 by 0.4 cm; apex acute; 6-7-nerved. Lateral sepals in basal half obliquely broad lanceolate, top half linear; apex acute; 7-nerved, 3.9 by 0.55-0.6 cm; mentum conical, obtuse, c.0.5 cm long. Petals linear, 3 by 0.15 m; apex acute; 5-nerved. Lip 3-lobed, 1.42 cm long; hypochile cuneate, 1 by 0.58 cm, inside on the lateral nerves laxly pubescent, the lateral lobes irregularly truncate, keel 1, plate-like, starting above the base and terminating below the apex of the hypochile, on the apex continuing on the base of the epichile with a patch of fine, subulate hairs; epichile lanceolate, 0.42 by 0.18 cm, upper surface densely covered with long club-shaped hairs, apex acute. Column semi-terete, 0.43 cm longr (0.38-0.4 cm without anther); column foot 0.5 cm long.
(after Ormerod, 2017)).
Leaf sheaths brown. Flowers purple, lip yellow.
Epiphytes in mossy upper hill oak forest. Altitude 900 m.
Distribution: Malesia, Papua New Guinea, endemic.
Papua New Guinea (Milne Bay Prov., Fergusson Isl.)
Warm growing epiphyte.
June.
- Family Orchidaceae
- Subfamily Epidendroideae
- Tribe Dendrobieae
- Subtribe Dendrobiinae
- Genus Dendrobium
- Section Grastidium
- Species Dendrobium polyrhopalon
Dendrobium polyrhopalon Ormerod is similar to D. quinquedentatum J.J.Sm. in the brown, minutely warty leaf sheaths, the rectangular to cuneate hypochile, and the small narrow epichile covered with long processes or hairs, but differs in the longer and broader leaves (to 7.5 by 1.2-1.35 versus 4.5 by 0.3-0.7 cm), larger flowers (sepals 3 versus 1.2-1.5 cm), and lip with a plate-like keel that begins well above the base of the hypochile (versus low and swollen, starting at the very base of the hypochile).
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Dendrobium polyrhopalon
Dendrobium polyrhopalon Ormerod, drawing by Paul Ormerod, in Checkl. Papuasian Orch. (2017) 243, 487 (fig.).