Dendrobium rugulosum

Dendrobium rugulosum J.J.Sm., Bull. Jard. Bot. Buitenzorg, sér. 2, 2 (1911) 10; Nova Guinea 12, 1 (1913) 51, t. 14, fig. 40.

Type: Kock, de 181 (holo BO, probable, s.n.).

Stems crowded, in cross-section elliptic, 27 cm by 1.5 mm, internodes 0.9-2.2 cm long. Leaf sheaths 0.23 cm wide. Leaves linear, twisted at the base so as to lie in one plane, 7.5-9.75 by 0.47-0.78 cm, papyraceous, apex strongly unequally bidentate. Inflorescences lateral from the stem, 2-flowered, spathe short. Pedicel and ovary 1.2 cm long. Flowers c. 2 cm across. Dorsal sepal 1.25 cm by 4.8 mm; mentum 0.43 cm long, truncate, slightly retuse. Petals 1.2 cm by 5 mm. Lip 3-lobed, when flattened 0.95 by 0.68 cm, on the lateral lobes inside with small transverse lamellae, on the midlobe transversely rugulose; midlobe 0.37 by 0.65 cm. Column 0.46 cm long; column-foot 0.43 cm long, towards the apex with 3 keels.
(after Smith, 1913).

Colours: Flower white, or sepals and petals white, lip in the centre yellow with white or sometimes lilac margins.

Habitat: Epiphyte in lowland forest, growing in the shade on smooth-barked trees. Altitude 0 to 150 m.

Flowering time in the wild: April, July.

Distribution: New Guinea (endemic).

Distribution in New Guinea: Papua (Jayapura and Jaya Wijaya Regencies).

Map: RUGULMAP.JPG [Dendrobium rugulosum J.J.Sm., distribution map.]

Notes: Dendrobium rugulosum is characterised by grass-like leaves, a 3-lobed lip without hairs, and white flowers.

Cultivation: Warm growing epiphyte, keep in shade.