Bulbophyllum nudicaule J.J.Verm., Schuit. & de Vogel, sp. nov.

(Fig. 15)

TYPE: Papua New Guinea, Central Province, Owen Stanley Range, Boridi, 4700 ft, 8 Sep. 1935, Carr 10263 (holotype L! 1495892; isotypes AMES!, BM, K!, L! 1495893, L! 1495894, NY!, SING 0132016).

DIAGNOSIS. Within series C, it shares the partly bare rhizome (not entirely covered by scales) with Bulbophyllum gymnothema and B. tricaudatum J.J. Verm. It differs from both by the coarsely papillose lip margins.

Rather large epiphyte with patent to pendulous, sparsely branched rhizomes to 80 cm long, over which the roots grow towards its base. Rhizome 3.0— 5.5 mm diam., sections between pseudobulbs 1.8–3.5 cm long, arising from the basal node of the pseudobulb; rhizome scales thin, leaving parts of the rhizome bare, little persistent. Pseudobulbs distinct, cylindrical, 2.8–5.3 × 0.5–0.6 cm. Leaf: petiole 2.5–7.0 mm long; blade ovate, 4.9–9.2 × 0.8–1.4 cm, ratio length/width 4.9–7.8; acute. Inflorescences solitary or few together, ca. 1.5 cm long, 1-flowered. Peduncle ca. 4.5 mm long, scales 1. Floral bracts ca. 4.6 mm long. Flowers: pedicel plus ovary ca. 4.6 mm long, basal node ca. 3.5 mm above the floral bract attachment. Median sepal free, recurved, elliptic to ovate, 6.0–7.2 × 3.3–4.2 mm, ratio length/width 1.5–2.1; acute, margins entire; glabrous; 3-veined. Lateral sepals as the median but ovate, 7.0–8.8 × 3.0– 4.3 mm, ratio length/width 1.8–3.0. Petals porrect, obovate-oblong, 3.0–3.8 × 0.8–1.2 mm, ratio length/width 3.0–3.8; obtuse, margins entire; glabrous; 1-veined. Lip slightly recurved close to the base, elliptic, 4.5–5.2 × 2.2–2.4 mm, ratio length/width 1.8–2.4 (without spreading); obtuse to acute, margins entire, coarsely papillose except near apex; rather thick; adaxially concave in the proximal 2/3 because of slightly upturned, coarsely papillose edges, with a v-shaped furrow near the base bordered by two low, finely papillose ridges which distally meet and continue as a rounded, rather narrow, glabrous median ridge up to 2/3 of the length of the lip, distal part of the lip slightly convex, adaxial surface otherwise glabrous; abaxially slightly convex, slightly furrowed distally, surface glabrous, papillose towards the edges. Column including stelidia 2.6–3.7 mm long, stigma obovate, foot distally widened and with spreading, rounded lateral teeth. Stelidia upwards falcate, narrowly triangular, 1.7–2.0 mm long, acute. Pollinia 4, the inner more than half as long as the outer.

COLOURS: sepals pale ochre, veins red-purple. Petals white, thickened part purple Lip purple, base and margins white, apex yellow.

ETYMOLOGY: nudus (Latin) = naked, caulis (Latin) = stem, referring to the rhizome which is not entirely covered by bracts.

HABITAT AND ECOLOGY: in forest on trees at 1425 m.