Aconitum kusnezoffii

Aconitum kusnezoffii belongs to Ranunculaceae, the buttercup family. It is a perennial, which means it lives for years. Bei Wu Tou is one of its common names. It is native to Siberia, Korea, and northern China. It grows in grasslands, on grassy slopes, and in forests. It also grows at forest edges and by streams. These sites include heights of 7,220–7,874 feet [2,200–2,400 metres].

The plant forms clumps and is deciduous: it sheds its leaves each year. Garden plants grow about 3.3–4.9 feet [1–1.5 metres] tall. They spread 0.3–1.6 feet [0.1–0.5 metres] wide. Dark stems rise above leaves with black stalks, called petioles. Each mid-green leaf has five to seven deeply cut lobes. Blue-purple, hood-shaped flowers grow in upright clusters called panicles. They bloom from late summer into early autumn. Plants take two to five years to reach full size.

Choose part shade and deep soil that stays cool and moist. Soil must drain well but still hold enough water. Full sun suits it too, if the soil stays moist. In sun, give it soil rich in humus. Add mulch during the growing season as well. It tolerates sand, loam, clay, and chalk. It also grows in acid, neutral, and alkaline soil. The RHS gives it a UK hardiness rating of H7. Plants For A Future lists USDA zones 5–9.

Its height and upright blooms give garden beds their shape. It suits cottage gardens and informal borders. It also suits woodland gardens with patches of shade. The RHS lists it for wildlife gardens too. Remove dead stems; it needs no other routine pruning. Divide clumps in autumn or late winter to make more plants. Doing this every few years may help it flower. Plants may take time to recover from division, though. Pests cause few problems, but aphids may occur. It may get fungal stem rot or powdery mildew. Verticillium wilt is another possible disease.

All parts are highly poisonous; none has a known food use. Eating the plant can poison people and pets. Touching it has caused numb skin in some people. Avoid direct contact when you handle the plant. Wear gloves and other gear that protects you. This includes when you divide plants or remove dead stems. Records note uses of the root as medicine. These include pain relief and sedation, which calms or induces sleep. Its poison makes home treatment unsafe. A qualified practitioner must oversee any use as medicine.