Dendrobium puniceum

Dendrobium puniceum Ridl., J. Bot. 24 (1886) 324.

Type: Forbes 425; 598 (syn BM).

Erect to suberect tufted epiphyte 2-8 cm high. Roots to 1.5 mm diameter. Rhizome usually very short, occasionally elongated to 5 mm Pseudobulbs 0.3-2.2 by 0.2-0.7 cm cylindrical, narrowly conical or obclavate, apex 1-2(-3) leaved. Leaves 1.0 5.4 by 0.25- l cm, linear, oblong, lanceolate or narrowly elliptic, subacute to obtuse, mucronate; sheaths slightly ribbed, with age becoming fibrous. Inflorescences terminal arising from both leafy and leafless stems, subsessile, commonly 2-flowered; bracts 4-l0 mm, ovate-apiculate. Flowers 1.3-2.2 cm, not or sometimes widely spreading to c. 1.8 cm wide, sometimes cleistogamous. Median sepal 5-9 by 2.5-3 mm, ovate-lanceolate, acute, mucronate, distinctly keeled. Lateral sepals 13-21 by 3-4.5 mm, obliquely triangular or lanceolate, acute to subacuminate, distinctly keeled; basal fused part 2-3 mm, conical to subconical usually distinctly contracted, tip obtuse; mentum total length 8-12 mm. Petals 4.5-8.5 by 1-2 mm, linear to linear-spathulate, widest at upper 1/3, acute. Lip 10-18 by 2-2.5 mm, linear to narrowly lanceolate, adnate to column foot at base with a transverse Y-shaped often indistinct ridge 2.5 mm long in basal ,),) 3, apical part free; apex subtrilobate, acute, downward bent or occasionally straight. Column 2-3 mm long; foot 8-12 mm long; anther 1.5-2 mm broad; pollinia c. l mm long. Ovary 5-winged, sometimes with 5 less distinct ribs or shallow wings alternating with main wings, dorsal wings projecting distinctly and shortly upward at base of dorsal sepal; pedicel and ovary 11-18 mm long. Fruit 9 by 5.5 mm, ovoid.
(after Reeve & Woods, 1989).

Colours: Flowers purplish red, blood red or orange-red, lip orange to yellow, apex sometimes tipped red.

Habitat: Epiphyte on small twigs, in moss or rainforest, one record from Agathis sp. Altitude 400 to 1700 m.

Flowering time in the wild: January, May, July, October and November.

Distribution: New Guinea, Bismarck Archipelago, Solomon Islands.

Distribution in New Guinea: Papua (Vogelkop Peninsula, Gautier Mountains, Mt. Carstenz); Papua New Guinea (Sandaun, Western Highlands, Southern Highlands, Madang, Morobe, Central and Milne Bay Provinces including Normanby, Misima and Tagula (Sudest) Islands; New Britain: West New Britain province).

Map: PUNICMAP.JPG [Dendrobium puniceum Ridl., distribution map, redrawn from T.M. Reeve & P.J.B. Woods, Notes Roy. Bot. Gard. Edinburgh 46 (1989) 288, map 12.]

Notes: The purplish red, blood-red or orange-red flowers, somewhat distinctively thickened leaves and 5-winged ovary with the wings sometimes alternating with less distinct ribs and the upper three wings at their apices projecting above the base of the dorsal sepal, are sufficient to distinguish this species from most others in the section Pedilonum.

Dendrobium seranicum from the Moluccas is probably the species most closely related to Dendrobium puniceum but is insufficiently known for assessment of the relationship. Dendrobium puniceum differs from Dendrobium seranicum in its shorter mentum and shorter basal fused part.

A cleistogamous population has been observed at Erave, Enga province.

Cultivation: Intermediate growing epiphyte. Probably requires a light, airy position and excellent drainage.
(after Reeve & Woods, 1989)