Marsdenia geminata (R.Br.) P.I.Forst.

Apocynaceae

Forster, P.I. (1995) Australian Systematic Botany 8: 805.

Vine stem diameter up to 5 cm recorded. Included bark present as radial lines like spokes in a wheel.

Twigs, leaves and petioles produce a milky exudate. Leaf blades about 3-9 x 1.5-5.5 cm, petioles about 0.6-1.7 cm long. Lower surface of the leaf blade densely clothed in hairs, upper surface more sparsely clothed. Petioles and leaf-bearing twigs densely clothed in pale coloured hairs. Lateral veins about 5-7 on each side of the midrib. About 1-9 colleters (short finger-like glands) visible on the upper surface of the leaf close to its junction with the petiole.

Inflorescence a very short umbelliform raceme. Flowers about 4-6 mm diam. Pedicels about 2-5 mm long, densely clothed in hairs. Sepals about 1-2 mm long, outer surface densely clothed in hairs. A very small stalked red gland is usually visible close to the base of and alternating with each sepal. Corolla tube about 1-2 mm long, densely clothed in hairs, lobes about 1-2 mm long. Five lobes on the inner surface of the corolla arch over the staminal corona. Stamens fused into a staminal column about 0.6-2 mm high. Anthers less than 1 mm long with a membranous wing-like appendage at the apex. Pollinia about 0.25 mm wide. Ovary about 1 mm long. Stigma globular, about 0.75 mm diam.

Individual fruiting carpels ovoid to fusiform, about 2.6-5 x 1.8-2.5 cm, surface densely clothed in short soft hairs. Seeds numerous, each seed about 7-8 mm long. Plumes white, about 15-25 mm long, attached at the end of the seed. Embryo about 6-7 mm long, cotyledons about 5.5 mm long, much wider than the radicle which is about 1.5 mm long.

Cotyledons elliptic to ovate, about 13-19 x 8-12 mm with 2-4 veins radiating from the base. First pair of leaves narrowly elliptic, apex obtuse, base rounded to cuneate. Small glands or gland-like stipules visible with a lens. Venation more conspicuous on the underside. At the tenth leaf stage: leaf blade lanceolate or narrowly elliptic to oblong, apex obtuse, base obtuse. Exudate meagre but appears quickly. Two small raised glands visible with a lens on the upper surface of the leaf blade near the midrib just above its junction with the petiole. Both the upper and lower surfaces of the leaf blade clothed in short simple hairs. Lateral veins about 4-6 on each side of the midrib. Stipules small and inconspicuous. Stems thick enclosed in fissured corky bark, at least towards the base. Seed germination time 14 to 35 days.

Occurs in WA, NT, CYP and NEQ. Altitudinal range from near sea level to 500 m. Grows in vine thicket and monsoon forest. Also occurs in New Guinea.

Gymnema sylvestre (Retz.) R.Br. ex Schult., : (). Gymnema geminatum R.Br., Prodromus Florae Novae Hollandiae : 462(1810), Type: islands of the Gulf of Carpentaria, Dec. 1802, R. Brown; lecto: BM; iso: BRI, MEL. Fide Forster (1989).