Swertia petiolata

Swertia petiolata is a perennial in the gentian family, Gentianaceae. Its native range runs from eastern Afghanistan to western Nepal. It grows in mountain habitats, from montane to alpine zones. Kew places it in subalpine or subarctic climates. This background fits its preference for cool summer weather. It is not native to Britain or Ireland.

Plants reach about 2 feet [0.6 metres] in height. Their spread is about 1.3 feet [0.4 metres]. These dimensions describe a small plant for the garden. The supplied sources give no details of its leaves or stems. They also give no account of its fruit. Flowers appear in July and August. Each flower has both male and female organs. The evidence does not name the insects or other agents involved in pollination.

Grow it in moist soil with plenty of humus. It suits damp woodland, stream edges, and bog gardens. Light shade, such as that beneath an open woodland canopy, suits it. PFAF also lists shaded garden edges as a planting site. The soil can stay moist or wet. Sandy soil, loam, and clay are all listed as suitable. It accepts mildly acid, neutral, and mildly alkaline conditions. PFAF gives a USDA hardiness range of zones 6–9. Its need for cool summers matters alongside that winter rating.

Seed provides a way to raise new plants. PFAF recommends spring sowing in a humus-rich growing medium. Keep sowing temperatures at or below 10°C. Move seedlings into separate pots once large enough to handle. Plant them out in early summer. Its stated garden roles centre on damp and shaded sites. The evidence gives no specific pest or disease problems. PFAF does not flag it as a weed.

PFAF lists no known food use for this species. It also reports no known hazards, which does not establish safety. The whole plant has a place in Tibetan medicine. Traditional uses include remedies for fever, inflammation, and liver complaints. Other listed uses concern high blood pressure and eye inflammation. These are reports of traditional practice, not proof of treatment benefit. The source describes the plant as bitter. It lists no other practical uses beyond those medicinal records.