Tylophora benthamii Tsiang

Apocynaceae

Tsiang, Ying (1936) Sunyatsenia 3: 231. Type: Mount Warning, Tweed River, N. S. W., C. Moore; holo: MEL.

Coast Tylophora; Tylophora, Coast

A slender vine not exceeding a stem diameter of 2 cm.

Twigs, petioles and leaves produce a yellow or creamy yellow exudate. Leaf blades about 7-11.5 x 4.5-8.2 cm, petioles about 1-3.5 cm long. Stems and petioles clothed in pale hairs. Lateral veins forming loops near the blade margin.

Flowers about 10 mm diam, at anthesis. Calyx lobes about 3 mm long. Corolla lobes about 7 mm long. Pollen aggregated in pollinia. One pollinia per anther locule. Stigma globular, sessile.

Individual fruiting carpels about 10.5 x 10 cm. Seeds numerous, each seed narrowly winged, about 9-10 mm long. Plume about 30 mm long, attached to one end of the seed. Embryo about 4.5-5 cm long. Cotyledons longer and narrower than the radicle.

Features not available.

Occurs in WA, NT, CYP, NEQ, CEQ with disjunct occurrences in south-eastern Queensland and north-eastern New South Wales. Altitudinal range in northern Australia from near sea level to 950 m. Grows in rain forest and monsoon forest. Appears to be endemic to Australia but may also extend into New Guinea.

This species may be used in Asian medicines.

A number of alkaloids were extracted from this species. Two of these alkaloids, viz. tylophorine and tylocrebrine, were active against a range of tumors. Limited clinical trials with tylocrebrine were conducted but were terminated because of evidence of irreversible effects on the central nervous system. Collins et al. (1990).

Care should be exercised handling large quantities of this species as some workers were temporarily blinded when employed for several days collecting large quantities of this species for drug evaluation.

Tylophora crebriflora S.T.Blake, Proceedings of the Royal Society of Queensland 59: 168(1948). Tylophora floribunda Benth., Flora Australiensis 4: 335(1868), Type: N.S. Wales. Mount Warning, Tweed river, C. Moore (Herb. F. Mueller, a single specimen). Vincetoxicum polyanthum Kuntze, Revisio Generum Plantarum 2: 424(1891).