Dendrobium subuliferum

Dendrobium subuliferum J.J.Sm., Bull. Jard. Bot. Buitenzorg, sér. 2, 2 (1911) 15; Nova Guinea 12, 1 (1913) 63, t. 17, fig. 51.

Type: Kock, de 199 (holo BO).

Erect, suberect or tufted epiphyte, 2-l0 cm high, often with ascending habit due to competition with mosses. Roots 0.4-l mm. Rhizome usually short, sometimes to c. l cm long. Pseudobulbs 0.5-2.5 by 0.15-0.35 cm, ovoid to narrowly fusiform, 3- 6-noded, apex 2- 4-leaved. Leaves 1-5 by 0.075-0.2 cm, erect to spreading, linear-subulate, thick, often rigid, midrib impressed above, lower surface convex apex acute or apiculate, sometimes minutely papillose; sheaths ribbed, with age becoming fibrous. Inflorescence terminal, mainly from leafy stems, 1- rarely 2-flowered, bracts 7 by 5 mm, scarious, ovate triangular, usually sheathing tip of mentum, distinctly 3-nerved, apex apiculate or acuminate. Flowers 1.5-2.2 cm, usually widely opening to 2.4 cm; sometimes fragrant. Median sepal 7-13 by 3-6 mm, ovate-triangular to ovate-elliptic, acuminate or apiculate. Lateral sepals 14.5-20 by 3.2-5.5 mm, ovate-oblong to ovate-elliptic, sometimes slightly keeled, strongly acuminate to subulate-acuminate; basal fused part 2-3 mm long, subconical; mentum total length 6-8 mm long, tip usually concealed by bract, obtuse or ( unequally) shortly bilobed. Petals 7.5-12 by 3.5-8 mm, broadly obovate-spathulate, upper margins often finely ciliate, apex apiculate. Lip 13-18 by 2.5-3.5 mm, simple to slightly trilobate, oblanceolate, adnate to column foot at base, margins of the apical part slightly upcurved, basal part with V-shaped transverse ridge, apex acuminate to narrowly triangular, straight or slightly deflexed, sometimes slightly upcurved. Column c. 2 mm long; foot 6-8 mm long, a blunt tooth at base present; anther 2-3 mm broad; pollinia c.0.6-0.8 mm long. Ovary 3-winged; pedicel and ovary 7-13 mm. Fruit not observed.
(after Reeve & Woods, 1989).

Colours: Flowers white, sometimes with red to purplish striations on inside of lip; anther usually purplish.

Habitat: Epiphyte in primary and secondary forest, occasionally terrestrial. Altitude 300 to 2000 (-2400) m.

Flowering time in the wild: January, April, May, November.

Distribution: New Guinea.

Distribution in New Guinea: Papua (Vogelkop Peninsula, Gautier Mountains, Mt. Goliath, Star Mountains, Tembagapura); Papua New Guinea (Sandaun, Southern Highlands and Morobe provinces).

Map: SUBULMAP.JPG [Dendrobium subuliferum J.J.Sm., distribution map, redrawn from T.M. Reeve & P.J.B. Woods, Notes Roy. Bot. Gard. Edinburgh 46 (1989) 285, map 6.]

Notes: This little known species with its beautiful white flowers and very distinctive broad petals is represented in herbaria by a mere handful of specimens from both West and East New Guinea all collected from between 300 and 2000 m, although P. van Royen (1979) included it in his Alpine Flora erroneously giving the altitude as 3000 m.

The field note accompanying Henty's collection (NGF 20885) from Telefomin states that the flowers were fragrant: only one other species in this section is known to have scented flowers - the closely related Dendrobium cyanocentrum from which it differs in its large predominantly white, usually single flowers with broad obovate-spathulate petals normally wider than the sepals: the sepals and petals are not reflexed. In habit, Dendrobium nardoides is not dissimilar but is easily differentiated by its purplish and mostly smaller flowers.
(after Reeve & Woods, 1989).

Cultivation: Intermediate growing epiphyte, keep in shade.