Hoya of Papuasia I. 
103 
Epiphytic climber with white latex in all vegetative parts. Stems cylindrical, stiff, 
2-3 m long, 1.5-3 mm in diameter, green to greyish brown, glabrous or sparsely 
pubescent; older stems leafless, up to 5 mm in diameter, greyish brown, glabrous with 
peeling bark; internodes (1—)3—15 cm long. Adventitious roots sparsely produced 
along the stem. Leaves petiolate; petiole terete, 1-2 x c. 1.5 mm in diameter, greyish 
green, glabrous; lamina linear-lanceolate, 1-2 mm thick, fleshy, 5-11 x 1-2.5 cm, 
bright to dark green on adaxial surface, light green on abaxial surface, glabrous, apex 
acute to acuminate, base round to attenuate, basal colleters 2, ovoid, 4-5 x 1.5-2 mm; 
venation pinnate, midrib depressed on adaxial surface, secondary veins 2-5 each side, 
barely evident in living material, more visible in dry material, diverging at 20-45°. 
Inflorescences one per node, extra-axillary, positively geotropic, convex, consisting of 
1-10 flowers; peduncle terete, c. 1 x 2 mm, older peduncles developing a rachis from 
previous flowerings, new peduncles glabrous or sparsely pubescent, older peduncles 
glabrous; pedicels terete, 10-15 x c. 1 mm in diameter, light green-yellow, often with 
red spots, papillate to glabrous, warty. Flower buds apically flattened, cream white to 
pale yellow with reddish spots. Calyx c. 3 mm in diameter, lobes deltoid, c. 1 x 1 mm, 
apex broadly acute to obtuse, margin sparsely ciliate; basal colleters one in each calyx 
lobe sinus, deltoid. Corolla rotate, concave, 1-1.5 cm in diameter (c. 1.5 cm when 
flattened), cream white to pale yellow, often with red spots on abaxial surface, also 
visible on the adaxial surface as pink spots; tube 3-3.5 mm long; lobes ovate, 4-5 x 
5-6 mm, adaxially thinly pubescent, denser at base of the corona, abaxially glabrous, 
apex acute, revolute. Corona staminal 1.5-1.7 mm high, c. 3.5 mm in diameter, fleshy, 
cream white to pale yellow with maroon centre; lobes obovate, c. 1.5 x 1-1.2 mm, 
inner processes slightly erect, apices acute, outer processes usually slightly erect to 
same level as inner processes, apex obtuse when observed from above, deeply grooved 
between inner and outer processes, not basally fused with the filament tube, with basal 
revolute margins. Style-head convex to same level as inner corona processes, hidden 
by anther appendages. Pollinia oblong slightly tapering at the base, with sterile edge, 
c. 450 x 200 pm, corpusculum squarish, c. 170 x 150 pm, caudicles attached at the 
sides of corpusculum, 70-100 pm long. Ovary broadly conical, glabrous. Fruits and 
seeds not observed. 
Distribution. Recorded only from one single locality at the confluence of Palmer River 
and Black River in the northwestern corner of PNG Western Province at 100-150 m. 
Etymology. Named after Leonard John Brass (1900-1971), an Australian botanist who 
collected the type specimen in 1936 on the Fly River Expedition of the Am erican 
Museum of National History (the second Archbold New Guinea Expedition). 
Habitat and ecology. At the type locality Hoya brassii is commonly found at the top of 
mature primary forest trees, in bright light conditions. It was absent in the understorey 
where the new taxon Hoya evelinae Simonsson & Rodda was instead abundant. 
