Bulbophyllum trivenosum J.J.Verm., Schuit. & de Vogel

Vermeulen, Jaap J., Schuiteman, André & De Vogel, Edward F., 2020, Sixteen new species of Bulbophyllum section Polymeres (Orchidaceae) from New Guinea, Lankesteriana 20 (3), pp. 301-330 : 317

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

( Fig. 11 )

TYPE: Papua New Guinea, East Sepik Province, Hunstein Range , 1500 m alt., 5 Oct. 1989, LAE (Katik & Kairo) 64395 (holotype L!; isotypes LAE, NSW) .

DIAGNOSIS. Most similar to Bulbophyllum ischnopus Schltr. and B. melinanthum Schltr. , differs from both by its 3-veined petals; in addition, it differs from the first by the shorter and thicker papillae on the abaxial surface of its lip, from the second by its oblong (versus ovate) petals.

Small epiphyte with creeping rhizomes and spreading roots. Rhizome 0.8—1.0 mm diam., sections between pseudobulbs 1.0–4.0 cm long, arising from the basal node of the pseudobulb; rhizome scales thin, little persistent. Pseudobulbs distinct, ovoid, 9.5–11 × 1.5–2.0 mm, (?)angular. Leaf: petiole 1.3–2.0 mm long; blade elliptic-oblong, 1.0–1.7 × 0.2–0.4 cm, ratio length/width 3.8—8.5; obtuse. Inflorescences single or a few together, ca. 3.5 cm long, 1-flowered. Peduncle ca. 1.9 cm long, scales ca. 2. Floral bracts ca. 2 mm long. Flowers: pedicel plus ovary ca. 9.5 mm long, basal node ca. 1.2 mm above the floral bract attachment. Median sepal free, recurved, elliptic, ca. 4.5 × 1.8 mm, ratio length/width ca. 2.5; acute-acuminate, margins entire, minutely papillose; glabrous, 3-veined. Lateral sepals as the median, but triangular, ca. 4.4 × 2.0 mm, ratio length/width 2.1, acute, margins glabrous. Petals porrect, oblong, ca. 2.1 × 1.0 mm, ratio length/width ca. 2.1; rounded, margins entire, minutely papillose, surface glabrous; 3-veined. Lip slightly curved, ovateoblong, slightly attenuated at ca. 1/3 of its length, ca. 2.8 × 0.8 mm, ratio length/width ca. 3.5 (without spreading); obtuse, margins entire, papillose at ca. 1/3 of its length, otherwise glabrous; thick; adaxially concave proximally, slightly concave distally, surface glabrous; abaxially with hardly a median furrow, convex, papillose but glabrous near base and apex. Column including stelidia ca. 1.7 mm long, stigma narrowly elliptic with the proximal edge slightly protruding, foot widened, with slight, patent, obtuse lateral teeth. Stelidia slightly downwards falcate, narrowly triangular, subulate distally, ca. 1.0 mm long, acute. Pollinia not seen..

COLOURS: flowers yellow and purple (?, label unclear).

ETYMOLOGY: tres (Latin) = three, venosus (Latin) veined.

HABITAT AND ECOLOGY: epiphyte in rainforest ca. 2 m above the ground. Elevation 1500 m.

Figures

FIGURE 11. Bulbophyllum trivenosum J.J.Verm., Schuit. & de Vogel. a. Habit. b. Flower. c. Flower analysis, from left to right: median sepal, petal, lateral sepal, lip.d. Lip, left: adaxial side, right: abaxial side.e. Column and lip, lateral view. f. Column, frontal view. Drawn from LAE (Katik & Kairo) 64395 by © J.J. Vermeulen, from herbarium material.