Pinellia tripartita aka Green Dragon

Pinellia tripartita is a tuberous perennial known as green dragon. It belongs to the arum family, Araceae. Its native range includes Hong Kong, South Korea, and Japan. It also grows in Japan's Nansei islands. Wild plants occur in woods, along woodland edges, and beside roads. They also grow in fields. Underground tubers support the leaves and flower stalks each year.

Garden plants reach about 1–1.5 feet [0.3–0.46 metres] tall. Some accounts give smaller heights, near 0.7 feet [0.2 metres]. RHS lists an upper height of 1.6 feet [0.5 metres]. Spread estimates differ more, from 1 foot [0.3 metres] to 3.3 feet [1 metre]. The plant forms clumps and loses its leaves seasonally. Each upright leaf stalk bears three green leaflets. Their shapes range from oval to oblong, with wavy edges. Leaflets may reach 0.25–0.67 feet [0.08–0.20 metres] long. The leaves have no hairs.

Flower stalks rise above the leaves from May to July. Each bears a narrow green spathe around a pale green spadix. The spadix extends beyond the spathe as a long tail. This structure may look like one flower, but it holds many flowers. The green display offers interest without bright flower colours. Small green berries follow the blooms. The plant can spread through seeds, tuber offsets, and bulbils.

Grow it in partial or full shade, including dappled light. It needs rich soil with humus and good drainage. Keep the soil moist, rather than letting it dry in summer. RHS lists clay, chalk, loam, and sand as suitable soils. It also accepts acid, neutral, or alkaline conditions. A sheltered spot suits it. Missouri Botanical Garden gives USDA zones 5–8; RHS rates it H7. Plants may take two to five years to reach full size.

Green dragon suits woodland beds, rock gardens, and shaded ground cover. It can also naturalize where conditions suit its growth. It spreads, but Missouri Botanical Garden does not regard it as invasive. Care needs are low, and it needs no pruning. Sources report few pest or disease problems. Plants For A Future lists no known food uses. It warns of possible calcium oxalate, while noting no confirmed toxicity record. It also records root uses for coughs and nausea. These reported uses do not establish safe home use.