Aristolochia indica L.

Linnaeus, C. (1753) Species Plantarum 2: 960. Type: India.

Birthwort

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

Leaf blades about 3.5-12 x 1.5-6.8 cm, petioles about 1.2-2.5 cm long.

Pedicel + ovary (hypanthium) about 25 mm long, one gradually tapering into the other. Perianth curved to almost U-shaped. Perianth tube about 30 mm long overall including the inflated base. Apical lobe about 30 x 10 mm. Stamens 6, fused to form a structure about 4-5 mm diam. Anthers sessile. Stigmas 6. Ovary 6-locular. Ovules numerous in each locule.

Capsules consist of a thickened seed bearing section about 3 cm long and a much thinner section also about 3 cm long which splits into a number of thread-like structures attached to the valves of the capsule. Seeds cordate, about 7-8 x 7-8 mm including the wing. Embryo minute, < 1 mm long, located in the pointed section of the seed.

Cotyledons glabrous, about 7-19 x 5-7 mm, petioles about 2 mm long. First leaf blade glabrous, about 8-10 x 3-5 mm with a petiole about 5 mm long. At the tenth leaf stage: leaf blade lanceolate, penninerved but 3-veined at the base, apex acuminate to caudate, base truncate. Two ridges, one on each side of the stem, run down from the point of attachment of each petiole. Petiole grooved on the upper surface.

An introduced species originally from India to Malaysia, now naturalised in NT. Altitudinal range probably quite small, the only collection seen being made just above sea level. Grows in monsoon forest.

Apparently only naturalised on Channel Island, Darwin Harbour, N.T. Ross & Halford (2007).