Bulbophyllum (section Codonosiphon Schltr.) leucoglossum Schuit., Juswara & Droissart, 2016

Juswara, Lina, Schuiteman, Andre & Droissart, Vincent, 2016, Four new orchid species from the Lengguru fold belt, West Papua, Indonesia, PhytoKeys 61, pp. 47-59 : 49

Bulbophyllum (section Codonosiphon Schltr.) leucoglossum Schuit., Juswara & Droissart sp. nov. Figs 2A , 3A-D

Diagnosis.

Similar to Bulbophyllum pyroglossum Schuit. & de Vogel because of the hinged lip and the hair-like appendages on the surface of the lip, but in that species the appendages are about four times longer, and they are discrete, subulate projections arranged in rows, not forming densely lacerate-fimbriate keels as in Bulbophyllum leucoglossum . Moreover, Bulbophyllum leucoglossum has two lamellae on the abaxial (concave) side of the lip; these are lacking in Bulbophyllum pyroglossum . The latter also has much broader and shorter petals, and an orange instead of a white lip.

Type.

Indonesia, West Papua Province, Kaimana Regency, Nusa Ulan village, Pegunungan Kumawa Nature Reserve, 04°0.3121'S, 133°5.1227'E, 15/11/2014, Droissart & Juswara 1789 (holotype: BO!, spirit material).

Description.

Epiphytic herb. Rhizome short, creeping; roots wiry, branching, 0.5 mm diam. Pseudobulbs closely spaced, light green, narrowly ovoid, 2.0-2.4 × 0.7-0.8 cm, with c. 10 longitudinal grooves, 1-leaved. Leaf deeper green, linear-elliptic, gradually narrowed towards the base, 8.8-10.3 × 1.3-1.4 cm, thin-coriaceous, apex acute. Inflorescences arising from the base of the pseudobulb, becoming fascicled, erect, 1-flowered. Peduncle wiry, erect-patent, 1-flowered, 7-9 cm long, glabrous, with two tubular, 4 mm long peduncle-scales. Floral bract tubular, strongly oblique, 4.5 mm long, apex acuminate. Pedicel-with-ovary terete, very slender, weakly 6-ribbed, almost straight or curved, c. 2.5 cm long, glabrous. Flowers opening widely, the sepals patent to reflexed; sepals and petals maroon; lip white, at base wine-red, basal part of the keels sulphur-yellow; column cream-colour tinged maroon, swollen basal part and foot light green; anther pale greenish. Dorsal sepal linear-oblong, 14.3 × 2.8 mm, 3-veined, apex acute. Lateral sepals free, obliquely linear-oblong, 13.4 × 3.3 mm, 3-veined, apex acute. Petals linear-oblong, slightly widened towards the base, glabrous, 2.6 × 0.8 mm, apex obtuse. Lip clawed, slightly mobile, attached to the column-foot by a 0.3 mm long, 0.4 mm wide ligament; claw in the basal half almost quadrangular, tapering towards the blade, 2.4 × 1.5 mm, glabrous, with erect, hemi-elliptic, lobe-like margins in the basal half; blade narrowly oblong, slightly tapering towards the apex, cucullate, strongly convex above, 9.7 × 2.3 mm, margins deflexed, finely lacerate-fimbriate; blade adaxially with one median keel and two lateral keels on each side, the keels finely lacerate-fimbriate; on the concave abaxial side with two lacerate-fimbriate lamellae; apex obtuse. Column 2.3 mm long, curved, strongly swollen at the base, with a short but distinct, thick, 1 mm long column-foot; apical column-wings each with two short obtuse teeth, the wings 0.4 mm wide; stigma in lateral view with protruding lower margin; anther helmet-shaped, 0.6 mm long, very slightly papillose; pollinia not seen.

Distribution and habitat.

Bulbophyllum leucoglossum is only known from the Lengguru fold belt in West Papua. It is currently recorded from a single location in the Kumawa Forest Reserve, near the village of Nusa Ulan (Fig. 1 ). The only population seen so far was found in submontane forest at 1005 m elevation, the plants growing epiphytically about 1.5 m from the ground on a slender, moss-grown, overhanging tree trunk in medium-sloping terrain. More than ten individuals were observed in the collecting locality, but only one was flowering at the time of our fieldwork (November).

Etymology.

From the Greek leuco -, white, and glossum, tongue, referring to the largely pure white lip.

Notes.

A distinctive species because of the five laciniate-fimbriate keels on the lip, which give it a hairy appearance. The only other known species in the large section Codonosiphon with a distinctly hairy-looking lip is Bulbophyllum pyroglossum Schuit. & de Vogel from Papua New Guinea, which is similar in plant habit and in the size of the flower. See the diagnosis for the main differences between the two species.

Figures

Figure 1. Main localities sampled during Lengguru 2014 expedition and distribution of the four new species in West Papua, Indonesia.

Figure 2. A Bulbophyllum leucoglossum: 1 flower 2 dorsal sepal 3 lateral sepal 4 petal; 5, lip, adaxial view 6 lip, abaxial view 7 detail of crest on lip 8 column and base of lip; all after Droissart & Juswara 1789; B Dendrobium centrosepalum: 1 flower 2 flower, lateral view 3 floral bract 4 dorsal sepal 5 lateral sepal 6 petal 7 lip 8 flower, cut open 9 column 10 anther 11 pollinia; all after Droissart & Juswara 1736; C Dendrobium taeniocaule: 1 flower 2 dorsal sepal 3 lateral sepal 4 petal 5 lip 6 mentum 7 column, lateral view 8 column, ventral view; all after Droissart & Juswara 1739; D Taeniophyllum pyriforme: 1 flower 2 dorsal sepal 3 lateral sepal 4 petal 5 lip 6 column 7 anther, dorsal view 8 anther, lateral view; all after Droissart & Juswara 1735. Single scale bar = 1 mm; double scale bar = 1 cm. Drawing: Judi Stone.

Figure 3. Photographs of living type specimens and habitats. Bulbophyllum leucoglossum: A habitat and habit B flower, side view C flower, front view D Flower close-up, showing details of the column and the labellum. Dendrobium centrosepalum: E habitat and habit F, G plant and inflorescence H inflorescence and flowers close-up. Photos: Vincent Droissart.