Stephania tuberosa Forman

Forman, L.L. (2007) Flora of Australia 2: 463. Type: Queensland, originally ex Cape York (cult. Brisbane) 1 Dec. 1971, D. Smith s.n. Holo: K. Iso: BRI, CANB, MEL.

Pumpkin Vine; Vine, Pumpkin

Vine stem diameters to 5 cm recorded. Deciduous, leafless for a period in May and June. Lenticels conspicuous. Stems attached to a large tuber (more than 50 cm diam.) on the surface of the ground. Small stems produce a red exudate.

Freshly cut twigs produce an orange-red exudate. Twigs usually longitudinally grooved. Leaf blades cordate to orbicular, peltate, about 5.5-16 x 5.5-15 cm, petioles about 6.5-18 cm long. Leaf blades much paler on the underside. About 10-14 veins, including the midrib, radiate from the point on the leaf where the petiole joins the leaf blade.

Male flowers: Flowers borne in inflorescences about 4-10 cm long. The flowers are borne in umbels and these umbels are then arranged in umbels. Primary peduncle about 40-45 mm long, secondary peduncles about 15 mm long. Flowers about 3 mm diam. Pedicels about 1 mm long. Sepals in two whorls each of three sepals. Sepals of the outer whorl obovate, about 1.7-2.5 x 1 mm. Sepals of the inner whorl orbicular, about 2 x 1.5 mm. Petals about 1.3-1.5 x 1.75 mm. Sepals and petals produce a red exudate when cut. Anthers borne in a peltate disk-like structure about 1 x 0.8 mm. Anther locules +/- forming a continuous gash.

Fruits laterally compressed about 7-8 x 5-6 mm, borne in pendulous umbel-like clusters on peduncles up to 80 mm long. Style remnant persisting near the base of the fruit. Style remnant about 3.5 mm long. Seeds laterally compressed, about 6-7 x 5 mm, resembling a small curled up prawn. Embryo U-shaped or horseshoe-shaped, about 11-13 mm long. Cotyledons curved, about 4 mm long, shorter than the curved radicle.

Seedlings glabrous. Cotyledons oblong, about 14-20 x 1.5-3 mm, apex bluntly pointed, sessile, venation longitudinal and parallel. First leaves simple, peltate, +/- orbicular, much paler on the underside, petiole at least as long as the leaf blade, venation palmate. At the tenth leaf stage: leaf blade +/- orbicular, peltate with about 5-7 main veins radiating from the point of attachment of the petiole. Underside of the leaf blade pale and glabrous. Petiole slender, about 25-35 mm long, usually longer than the leaf blade. Stem and root thickened like a carrot (Daucus carota). Seed germination time 31 to 325 days.

Endemic to Queensland, occurs in CYP and NEQ. Altitudinal range from near sea level to 550 m. Grows in monsoon forest and the drier more seasonal rain forests.