Dregea sinensis Hemsl., syn. Watakaka sinensis (Hemsl.) Stapf (Asclepiadaceae) A deciduous climber with heart-shaped leaves and hanging umbels of scented pink or white flowers, native of W China in W Hubei, Sichuan and Yunnan, growing in scrub in rocky places at 40–2400m, flowering in May–July. Climber to 2.5m; leaves softly greyish-hairy beneath, to 10cm long. Flowers 1.5cm across, in umbels to 8cm across. For any good soil in sun or partial shade. Min. 15°C, perhaps with protection for the root. A nearly hardy Hoya-like climber.

Dregea E. Mey. (1837), in the family Asclepiadaceae, formerly often called Watakaka, contains 3 or 4 species in Asia and East Africa.

Description Climbers to 3m, woody at the base, with a milky sap. The leaves are opposite, evergreen or deciduous, softly hairy, stalked, simple, cordate. The flowers are scented, pale pink, white, or yellowish, with red or purple spotting, in stalked umbels in the leaf axils. Sepals 5, small, joined at the base. Petals 5, joined at the base, hairy on the edges. Stamens 5, held close around the stigma. Pollen is aggregated into sticky masses. Ovary superior, 2-celled, with numerous ovules per cell; style 1. Pollination is by insects, especially butterflies and moths. The fruits are green and curved with a long, tapering point, sometimes crested, splitting to release the seeds, which have a tuft of silky hairs at the apex.

Key Recognition Features The opposite, velvety leaves and stalked umbels of white or pale pink, starry flowers speckled with purple or red.

Evolution and Relationships The commonly grown D. sinensis Hemsl. is similar to Hoya carnosa R. Br., but that has very thick, smooth, and fleshy evergreen leaves and flowers that are unmarked and in tighter umbels.
Ecology and Geography In dry scrub and scrambling over rocks; 2 species from India to western China and 1 in East Africa.

Comment Dregea sinensis is an attractive climber suitable for a dry position. The leaves of D. abyssinica (Hochst.) Schumann are eaten cooked in Uganda.