Distimake tuberosus / Merremia tuberosa / Batatas tuberosa – Spanish Arborvine, Wood Rose, Yellow Morning-Glory

Description

Flowers: 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.

Fruit: 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.

Leaves: 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.

Seedlings: 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.