Ipomoea hederifolia L.

Linnaeus, C. von (1759) Systema naturae ed. 10 : 925. Type: Ind. Occ.

Cardinal's Flower; Ipomoea, Star; Star Ipomoea; Scarlet Creeper; Creeper, Scarlet

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

Lateral veins raised on the upper surface of the leaf blade. Domatia poorly developed, consisting of a few hairs in the axils of the basal veins.

Inflorescence looks like a raceme at first sight but each flower appears to be terminal and the inflorescence is extended by a succession of axillary shoots. Each sepal ending in a horn-like appendage about 2-3 mm long which projects out from the flower axis at an acute angle. Corolla bright red (scarlet) lobes induplicate valvate. Basal part of the staminal filaments clothed in short warty trichomes. Pollen grains white, minutely spinulose. Stigma +/- globular, composed of numerous short stump-like branches each of which ends in a hairy tip. Staminal filaments and style projecting beyond the corolla at anthesis.

Fruits globular, about 6-7 mm diam., sepals awned, persistent at the base. Seeds about 3.5-5 mm long. Testa clothed in short erect hairs. Hilum +/- orbicular, about 0.5 mm diam. Endosperm not abundant and not obvious. Cotyledons folded many times in a complex manner. Radicle slightly curved, about 3 mm long.

Cotyledons about 13-35 x 18-41 mm, lobed or deeply notched at the apex. Petioles about as long as the cotyledons. Cotyledons three or five-veined, the midrib not extending to the apex. First leaves cordate, apex acuminate, base auriculate to cordate, +/- 7-veined at the base, midrib and major veins raised on the upper surface, margins usually sparsely toothed. At the tenth leaf stage: leaf blade cordate, about 3-4 x 2-3 cm, apex acuminate, base cordate, petioles 1.5-3 cm long. Usually the midrib and four other veins radiating from the base. Midrib and major lateral veins raised on the upper surface. Stems clothed in pale +/- prostrate hairs, leaves almost glabrous. Stems twining. Seed germination time 10 to 26 days.

An introduced species originally from tropical America, now pantropic and naturalised in WA, NT, CYP, NEQ, CEQ and southwards as far as north-eastern New South Wales. Altitudinal range in northern Australia from near sea level to 750 m. Usually grows as a weed on agricultural land but also found in open forest and rain forest margins.