Smilax china aka Chinaroot

Smilax china, or China root, is a deciduous climber in the Smilacaceae family. It comes from East Asia, including China, Korea, Japan, and Taiwan. It is not native to Britain or Ireland. In the wild, it grows in forests, thickets, and hills. It also occurs on grassy slopes and beside shaded streams. Its range extends from near sea level into mountain country.

This vine reaches about 15 feet [4.5 metres] in height. It climbs through small trees and shrubs for support. Tendrils and thorns help it hold onto nearby growth. Its climbing habit suits the edge of a woodland garden. It can also grow in areas with dappled shade. The plant loses its leaves rather than keeping them year-round. Its large, fleshy roots store starch and have several recorded uses.

Flowers appear in May, and seeds ripen in October. Each plant bears either male flowers or female flowers. A single plant cannot fertilise itself. Grow both sexes if you want to raise seed. The fruit measures about 0.35 inches across and is edible raw. People also eat the young shoots and leaves, raw or cooked. Leaves can serve as a cooked green or make tea. The roots need cooking before use as food. Dried roots can also be ground into flour.

Choose moist soil that drains well, in sun or partial shade. The plant accepts sandy soil, loam, and clay. It also tolerates mildly acid, neutral, and mildly alkaline ground. PFAF lists USDA zones 5–9 and cold tolerance near −15°C. These are separate guides to its hardiness, not exact equivalents. A plant at Kew has grown well beside a west-facing wall. Small trees or shrubs can provide its climbing support.

The roots and leaves also yield dyes for practical use. Alum produces yellow shades, while iron sulphate produces brown. The root has a history of medicinal use for several ailments. These include skin complaints, joint pain, and urinary problems. Such uses do not establish that treatment works or is safe. Large medicinal doses can cause nausea and vomiting. PFAF lists no other known hazards and flags no weed potential. Its medicinal notes distinguish this species from the true medicinal China root.