Girardinia diversifolia aka Himalayan Nettle

Girardinia diversifolia has two common names: Himalayan nettle and Nilgiri nettle. It forms part of the nettle family, Urticaceae. It comes from tropical and subtropical parts of the Old World. Sources place it across much of Asia and tropical Africa. It grows near streams, forest edges, and villages. It also grows on ground that people have disturbed. In Nepal, it grows in moist woods with shade, too.

This upright plant can live for one year or more. Its size and form vary a great deal. Useful Tropical Plants gives heights of 0.8–8.2 feet [0.25–2.5 metres]. PFAF gives an upper height of about 10 feet [3 metres]. The straight stems may branch or stay single. Their bases can turn woody as they age. Thick coats of stinging hairs cover the stems and leaves. Touching them can cause strong pain for minutes or hours.

PFAF lists the bloom time as September to October. Seeds then ripen from October to November. Some plants may bear just male or just female flowers. Others carry both sexes on the same plant. When the sexes grow apart, seed needs plants of both sexes. People cook young leaves and flower clusters as greens. Heat stops the hairs from stinging. Those who pick them must still avoid skin contact. People have also used the seeds to poison fish.

This nettle needs moist soil when grown in gardens. It can grow in sun or part shade. It accepts sand, loam, and clay soils. Soil can range from slightly acid to slightly alkaline. Useful Tropical Plants places it in warm temperate and tropical climates. PFAF does not confirm that it can live outdoors in Britain. The sources give no firm range for frost hardiness. PFAF suggests sowing seed under glass in early spring. It also suggests splitting roots to make more plants.

People grow this plant for food, fibre, and local medicines. Fibres from its stems make cloth, rope, and twine. Growers in southern India raise it for this use. Nepal sometimes exports goods made from the fibre. Folk remedies use the roots, stems, leaves, and plant ash. People use these for fever, stomach complaints, and skin problems. These records of folk use do not prove safe treatment. The strong sting poses a clear risk when handling plants. The supplied sources name no specific pest or disease problems.