Vine to many metres high, latex clear. Leaves of 2 kinds. Adult leaves thick to leathery; blade narrow-lanceolate to lanceolate-ovate, 3.5-13 cm long, 1-4 cm wide; tip acute to long-pointed; base cuneate. Corolla yellow, 4-5 mm long. Fruits narrowovoid, 5-10 cm long, 0.9-1.2 cm wide.

Australia

 

The native P. straminea (R. Br.) F. Muell., Common Silkpod, is a vine to many metres high, latex clear. Leaves of 2-3 kinds, the adult leaves thick; blade elliptic to oblong-ovate, 4-24 cm long, 1.5-8 cm wide; tip acute; base cordate to rounded. Corolla cream, yellowish or pink, 7-8 mm long. Fruits tapering to each end, terete, 10-20 cm long, about 1 cm wide.

Source: Forster, P. (2002). Apocynaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.