Distimake tuberosus (L.) A.R.Simoes & Staples

Simoes, A.R. & Staples, G.W. (2017) Botanical Journal of the Linnean Society 183: 575.

Spanish Arbour-Vine; Wood Rose

Vine stem diameters to 3 cm recorded. Milky exudate copious.

Leaf blades deeply and palmately divided usually with 7 lobes, leaf blades about 8.5-14 x 9.5-18 cm overall, petioles about 5.5-12 cm long. Oil dots streaky. Each lobe of the leaf blade has a major middle vein and attached lateral veins. Stems and petioles produce a milky exudate.

Inflorescence a 2 to 7-flowered raceme about 7-13 cm long. Calyx lobes glabrous, about 30 x 20-25 mm clasping the base of the flower. Corolla trumpet-shaped, about 4.5-5.5 x 5 cm. Stamens irregular in length, about 6-18 mm long. Filaments thickened and hairy towards the base. Anthers about 6 mm long with two rows of glands on the back. Disk about 1.5 mm high, surrounding the ovary. Ovary globose, about 3 mm diam. Style about 15 mm long. Stigma globose, 4-lobed. Ovules 2 per locule.

Fruits globose, about 3.5-4 cm diam., enclosed by the persistent sepals forming a structure about 8-10 cm diam. Seeds 1-4 per fruit, each seed about 20 x 15 x 10 mm, clothed in black prostrate hairs.

First leaves glabrous, deeply and narrowly palmately five-lobed. At the tenth leaf stage: leaf blade palmatisect, five-lobed, sometimes appearing seven-lobed because of additional lobing on the basal pair of lobes. Midrib and lateral veins depressed on the upper surface. Minute oil dots barely visible with a lens. Plant twining. Seed germination time 34 days.

An introduced species probably originating in tropical America, now naturalised in tropical Africa, the Mascarenes, India and Sri Lanka. Occurs in NEQ and CEQ. Altitudinal range in NEQ from near sea level to 300 m. Grows on the margins of lowland rain forest.

This species may have medicinal properties. It is also used as a hallucinogen.

Merremia tuberosa (L.) Rendle, Flora Tropical Africa 4: 104 (1905). Ipomoea tuberosa L., Species Plantarum : 160(1753), Type: Tropical regions.