Dendrobium viridiflorum

Dendrobium viridiflorum F.M.Bailey, Queensland Agric. J. 2 (1897) 285.

Type: Dixon cult. (Steele) s.n. (New Guinea) (not located).

Rhizome creeping, 5-15 cm long. Roots papillose. Stems 1-2 cm apart, erect, flexuose, at the base slender, terete, otherwise swollen and somewhat bilaterally flattened, grooved, leafy, 10-26 cm long, at base 1.7, near the middle 9 mm diameter, internodes 1.5-2.5 cm long, shorter in upper part. Leaves patent, lanceolate, 5-7.5 by 0.6-1.15 cm, apex obtuse, unequally bilobulate. Inflorescences arising laterally from nodes of the swollen part of the stem, from the outer angles, short, branching and re-branching with age, each branch 1-flowered, main axis c. 5-6 mm long, branches c. 3 mm long, total inflorescence up to 6-flowered, but apparently always only 1 flower open, peduncle-scales short, tubular. Floral bracts triangular, 0.13 cm long, apex acute. Pedicel 0.65 cm long, slender, at an obtuse angle to the ovary; ovary 0.2 cm long, obconical. Flowers resupinated, 1.2 cm long. Dorsal sepal oblong, 0.55 cm by 2.7 mm, strongly concave, 5-nerved, apex subacute. Lateral sepals triangular, 0.5 cm by 0.6 mm, apex acute; 5-nerved; mentum spur-like, narrowly conical, 0.7 cm long, of which apical closed part 0.35 cm long, laterally flattened, at an obtuse angle to the basal part, apex obtuse. Petals lanceolate, slightly contracted above the base, 0.46 cm by 1.5 mm, 3-nerved, margins minutely erose, apex subacute. Lip 3-lobed at one quarter from the apex, strongly recurved, 0.67 by 0.4 cm, with a short claw, adnate to the column-foot at the base, margins near the base fimbriate-erose, with a median swollen band which terminates on the claw in a short, obtuse, retuse appendage; lateral lobes pointing upwards, oblong-triangular, 0.4 by 0.3 cm, concave, obtuse; midlobe cuneate, narrowing to a basal claw, with a basal thickening which extends to near the middle, apex rounded-truncate. Column short, , stelidia obtuse; column-foot 0.7 cm long, divided into two parts: basal part 0.35 cm long, curved, channelled, apical part 0.35 cm long, at an obtuse angle to the basal part.
(largely after Smith, 1904 - as Dendrobium zippelii).

Colours: Sepals pale green, petals and lip white.

Habitat: Epiphyte in mangrove swamps and coastal forest. Altitude 0 to 200 m.

Flowering time in the wild: January, March, June-October.

Distribution: Moluccas, New Guinea, Solomon Islands.

Distribution in New Guinea: Papua (Biak Numfor, Yapen-Waropen, and Jayapura Regencies; Waigeo Island); Papua New Guinea (Morobe Province).

Notes: Dendrobium viridiflorum is an insignificant but highly interesting species, as it is among the few orchids that prefer to grow in mangrove swamps, and even more so because the inflorescences are quite unusual. The latter are like tiny sympodia, producing up to 6 branches in succession, each terminating in a single flower.

Cultivation: Warm growing epiphyte.