Ipomoea aculeata Blume

Blume, C.L. von (1826), Bijdragen tot de Flora van Nederlandsch Indie 13: 715.

A fast-growing vigorous vine. Vine stem diameters to 3 cm recorded. Bark exudate watery. Included bark visible as curved segments in transverse sections of the stem. Stems somewhat fluted with a twisted appearance.

Leaf blades cordate with the apex drawn out into a long point. Leaf blades about 7-13 x 5-11 cm, petioles about 3-11.5 cm long. Stems, petioles and both the upper and lower leaf blade surfaces clothed in pale hairs. Stems clothed in small but hard spines. Stems and petioles produce a clear exudate.

Flowers pleasantly perfumed when fresh. Outer sepals about 20 x 18 mm, inner sepals much smaller. Corolla about 12-13 x 7 cm diam. at the apex. Corolla tube pale green on the outer surface, expanded section mainly white except for the pale green lobe-like sections. Corolla tube glabrous on the outer surface but hairy on the inner surface at least near the point of attachment of the stamens. Stamens attached about half way up the corolla tube, filaments about 2.5-3 cm long, clothed in white hairs at least towards the base. Pollen grains white, minutely spinulose. Disk thick, white and fleshy, surrounding the base of the ovary. Style about 9-10 cm long. Stigma +/- globular, multilobed and papillose.

Fruits enclosed in persistent sepals, each sepal about 16 mm long. Fruits globose, about 12-15 mm diam. Seeds 2-4 per fruit, testa densely clothed in woolly pale brown hairs. Seeds about 7 mm long. Hairs about 10 mm long. Endosperm very hard. Cotyledons crumpled and folded in a complex fashion. Radicle about 3 mm long, much narrower than the cotyledons.

Cotyledons bilobed, about 55 x 45 mm, three or five-veined. First pair of leaf blades cordate, apex acuminate, base cordate. Petioles ornamented or armed with curved, thorn-like projections. At the tenth leaf stage: leaf blade cordate, apex acuminate, base cordate. Venation +/- palmate, midrib slightly raised on the upper surface. Both the upper and lower surfaces of the leaf blade clothed in translucent hairs. Two large, domed, shiny glands present on the petiole near its junction with the leaf blade. Numerous large, green, vertically elongated trichomes present on the petioles and stem. Taproot thickened. Seed germination time 61 days.

Occurs in CYP. Altitudinal range probably not great, known only from one collection made about 30 m above sea level. Grows in gallery forest. Also occurs in Asia and Malesia.