Arisaema flavum aka Yellow Cobra Lily

Arisaema flavum, or yellow cobra lily, belongs to the arum family, Araceae. Its native range spans northeastern tropical Africa to south-central China. It is not native to Britain or Ireland. This tuberous perennial grows in temperate regions. Recorded habitats include mountain slopes, field edges, and roadsides. In Tibet, it grows in high-elevation steppe. In Kashmir, it occurs on soils rich in humus.

The plant has an upright form and loses its leaves each year. It reaches about 1.3 feet (0.4 metres) tall. The RHS gives an upper garden height of 1.6 feet (0.5 metres). Its listed spread also reaches 1.6 feet (0.5 metres). Plants take five to ten years to reach full size. Dark green, lobed leaves emerge with the flowers in early summer. Flowering runs through June and July. A bright yellow, hooded spathe surrounds a yellow spadix. A dark purple patch marks the inside of the hood.

Grow it in a cool, sheltered spot with partial shade. It suits woodland gardens and shaded edges, but not deep shade. The soil should hold moisture yet drain well. Add humus, and choose sandy or loamy soil. Acid to neutral soil suits it. Plant tubers in winter or spring, about 0.7 feet (0.2 metres) deep. Do not let dormant tubers dry out. Avoid waterlogged soil in winter. The RHS rates it H6 for UK hardiness. In colder areas, leaf mould mulch can help protect the tubers.

This small plant suits containers, flower beds, and informal gardens. It also fits beneath roses and shrubs in sheltered sites. No pruning is needed. Sow seed in containers in a cold frame during autumn or spring. Remove offsets in late summer to make more plants. Slugs and vine weevil may attack it. The RHS reports few disease problems.

All parts need care when handled or eaten. The RHS warns of harm to people and pets if swallowed. Contact can also irritate skin and eyes, so wear gloves. Calcium oxalate crystals can cause sharp pain in the mouth. PFAF records cooked young leaves as a vegetable, with a toxicity warning. This reported food use does not make raw leaves safe. PFAF also records medicinal and pesticide uses. These records do not establish safe home treatments.