Orchids of New Guinea

Bulbophyllum irianae

Bulbophyllum irianae De Vogel, Suhartawan, Hoogendijk & Heatubun, OrchideenJ. 6, 5 (2018) 3, fig. (E-published 5-X-2018)

Type: Keerom cult. s.n. (De Vogel, Suhartawan & Hoogendijk) (holotype Yayasan Pendidikan Alam Papua, temporarily stored in Universitas Cenderawasih)

Epiphyte, creeping. Roots terete, minutely pustulate, c. 0.08 cm diam. Rhizome c. 0.3 cm diam.; rhizome scales not persistent. Pseudobulbs 0.6-1 cm apart, ascending, hardly narrowing to the top, dorsoventrally flattened, 0.6-1 by 0.2-0.4 cm, to c, 0.2 cm thick, finely irregularly longitudinally grooved. Leaf thick coriaceous, 4.7-10.2 by 2.1-2.6 cm; petiole 0.2-0.7 by 1.5-2 cm; blade elliptic, 4.5-10 by 1.4-2.6 cm, index 3.1- 3.8, with rounded apex. Inflorescence c. 11.7 cm long, 1-flowered; peduncle c. 7.7 cm long cm long; peduncle scales 3; tubular, the upper one with a long acuminate top; floral bract tubular, c. 0.7 cm long, with a long acuminate top; node displaced c. 0.9 cm. Pedicel and ovary c. 4 cm long; the ovary c. 0.6 cm, with 6 grooves. Median sepal porrect, c. 1.6 by 0.35 cm, index c. 4.57, entirely glabrous; widened basal part elliptic, thin and convex, c. 0.8 cm long, index c. 2.29, with entire margins, nerves 3,-raised, the lateral nerves with one branch from near the base; apex a long, solid, terete, subulate awl c. 0.8 cm long, which is adaxially in the lower half flat, without crest or keel, continuously and gradually narrowing in the very thin tip. Lateral sepals free, c. 8.2 by 0.6 cm, index c.13.5, entirely glabrous but basal half on inner side slightly rugulose; basal part widened, oblique and somewhat falcate near the base, c. 2.5 cm long, long ovate, index c. 4.2, with upper margin minutely irregular, lower margin smooth, 4-nerved with the upper 2 nerves and the lowermost nerve branching at the very base; apical part long drawn-out, narrow, c. 5.5 by 0.07-0.1 cm, with c. parallel margins, its basal part thin, the top 4 cm subulate and c. semi-terete, spiraling around each other with c. 6 turns, with acute apex. Petals porrect, obovate-oblong, c. 0.52 by 0.17 cm, index c. 3, entirely glabrous; margins entire, smooth; apex acute to acuminate, curved downwards; 3-nerved, the median nerve more pronounced. Lip recurved over its entire length, c. narrowly ovate with a slightly widened base, c. 0.33 by 0.09 cm, index c. 3.7 (without artificial spreading), entirely glabrous; margins entire, at the back of the lip elevated with sharp margins; upper side smooth, without ornamentation; below with a broad high base which is elevated where the ligament is attached and which narrows and lowers to near the top of the lip into a high crest; apex narrowly triangular, acute. Column c. 0.27 cm long; rostellum not protruding; stigma elliptic; column foot c. 0.25 cm long, its apex free for c. 0.1 cm strongly curved upwards, somewhat widened; stelidia porrect, triangular, acute.
(after Schuiteman, de Vogel, Heatubun, Wamma, Mambor, Suhartawan & Hoogendijk 2018)

Colours:

Median sepal reddish, the margins and top half lighter ochrish tinged reddish. Lateral sepals warm red, the facing margins in the basal free part near the attachment lighter ochrish red, turning whitish tinged pale red, continuing to where the sepals connect. Petals light ochrish tinged red, the nerves slightly darker red. Lip on upper side and lateral above purplish red, the lower side lighter reddish tinged ochrish. Column reddish, anther light ochrish

Habitat:

Canopy epiphyte in slightly disturbed rain forest c. 45 m high, with much undergrowth. Terrain undulating to steep. Altitude c. 300 m.

Distribution:

Malesia (New Guinea), endemic

Distribution New Guinea:

Indonesia (Papua Prov., Keerom Regency)

Cultivation:

Warm growing epiphyte

Flowering time in the wild:

February

Classification:

Family Orchidaceae
Tribe Dendrobieae
Subtribe Bulbophyllinae
Genus Bulbophyllum
Section Peltopus
Species Bulbophyllum irianae

Notes:

Bulbophyllum irianae is similar to B. obovatifolium J.J.Sm., but differs in the apex of the median sepal which is a long, solid, terete, subulate awl c. 0.8 cm long that is adaxially in the lower half flat, has no crest or keel, and narrows continuously and gradually into the very thin, narrowly acute tip (versus median sepal keeled, acute, concave, the top half in the middle conduplicate, laterally compressed); the lip from above slender narrowly triangular with a narrowly acute apex and a smooth upper surface without ornamentation (versus lip from above tongue-shaped with an obtuse apex and a channeled upper side with two ribs and a low small rib in the middle); lateral sepals c. 8.2 cm long and 6 times twisted around each-other (versus lateral sepals c. 4.5 cm long and not twisted).

Bulbophyllum harposepalum Schltr., often treated as a synonym of B. obovatifolium, differs from B. irianae in the much smaller, not twisted sepals, the broader and obtuse lip with a median depression and obtuse apex, and in the median sepal which is towards the top conduplicate-compressed and keel-like, rather blunt, not gradually tapering.

Bulbophyllum irianae, is named in honour of Lady Iriana Joko Widodo, First Lady of Indonesia, at the occasion of the 2018 International Conference on Biodiversity, Ecotourism, and Creative Economy (ICBE), Manokwari, 2018, in recognition of her efforts to stimulate and support the development processes in Papua.