Orchids of New Guinea

Dendrobium taeniocaule

Dendrobium taeniocaule Schuit., Juswara & Droissart, PhytoKeys 61 (2016) 54, fig. 2c; 4a-e.

Type: Droissart & Juswara 1739 (holo BO, spirit material).

Epiphytic herb. Roots 0.1 cm diam., minutely verrucose. Rhizome short, creeping. Pseudobulbs erect, elongate, bilaterally flattened, 16–21 by 0.4–0.5 cm; internodes 2.3–2.6 cm long, each internode narrowed towards the base; leafy throughout except for two or three basal internodes, with 6–8-leaved. Leaves long-lived, patent, oblong, 2–3.3 by 0.6–0.9 cm; sheath much shorter than the internode; apex unequally bilobed. Inflorescence 1-flowered, arising from the apex of the internodes in the upper part of the stem, sympodially branching with age with up to 3 branches, each branch 0.3–0.8 cm long; peduncle c. 0.6 cm long, its basal part covered with scales. Floral bract triangular, closely appressed, 0.29 cm long; apex apiculate. Pedicel 0.26 cm long; ovary at right angles to the pedicel, 0.26 cm long, glabrous; at the base of the pedicel with an abortive rachis. Flower 1.03 cm high, glabrous. Median sepal broadly ovate, 0.41 by 0.33 cm; apex obtuse; 5-nerved. Lateral sepals obliquely broadly ovate, the free part 0.53 by 0.43 cm; apex obtuse; 5-nerved; mentum cylindrical, 0.36 cm long, with rounded apex, the closed apical part 0.28 cm long. Petals linear-oblong, 0.44 by 0.12 cm; margin in upper third finely papillose; apex acuminate; 3-nerved. Lip 3-lobed, clawed, when flattened 0.67 by 0.85 cm excluding the c. 0.4 cm long, linear claw; lateral lobes subfalcate-oblong, patent, 0.27 by 0.1 cm; midlobe clawed, bilobulate (the whole lip appearing 4-lobulate), 0.57 by 0.85 cm; midlobe claw obtrapeziform, 0.17 by 0.44. cm; lobules of the midlobe rectangular-orbicular, 0.33 by 0.42 cm; the whole of the lip, except for the lateral lobes and the lobules of the midlobe, occupied by a sharply delimited swelling, which has two broad longitudinal crests with a narrow rib in between and which projects backwards over the claw of the lip for 0.03 cm. Column broadly conical in front view, 0.17 cm long; wings very short, truncate; column foot 0.36 cm long; stigma large, 0.16 cm wide; rostellum a simple transverse ridge; anther cucullate-rectangular, 0.11 cm wide, glabrous; pollinia not seen.
(after Schuiteman, Juswara & Droissart 2016)

Colours:

Pseudobulbs yellowish green. Leaves deep green. Sepals greenish white, tinged pale purple abaxially and on the mentum. Petals pale green. Lip white. Column pale green suffused with purple; anther pale green.

Habitat:

Epiphyte on a vertical, lichen-covered trunk of a tree in submontane forest. Altitude 1114 m .

Distribution:

Malesia (New Guinea, endemic)

Distribution New Guinea:

Indonesia (West Papua Prov., Kaimana Regency), see map

Cultivation:

Intermediate growing epiphyte.

Flowering time in the wild:

October

Classification:

Family Orchidaceae
Subfamily Epidendroideae
Tribe Dendrobieae
Subtribe Dendrobiinae
Genus Dendrobium
Section Calyptrochilus
Species Dendrobium taeniocaule

Notes:

Dendrobium taeniocaule is similar to Dendrobium viridiflorum in the flattened stems and the sympodially branching inflorescences with 1-flowered branches, but differs in the relatively much shorter mentum (0.36 cm versus 0.7 cm long) combind with the c.equal in length of the free part of the lip, the relatively much broader median sepal, the lip being wider than long (versus longer than wide), and the much wider midlobe of the lip (0.85 versus 0.32 cm) which is bilobulate (not entire).