Stillingia sylvatica aka Queen's Delight

Stillingia sylvatica is in the spurge family, Euphorbiaceae. People call it queen's delight, queen's root, and silver leaf. The RHS lists two more names: yaw root and nettle potato. Kew says it is native to the central and southeastern United States. Kew also says it suits a subtropical climate. It is not native to Britain or Ireland. In Texas, it grows in sandy prairies and open woods. It grows on open ground there too.

This plant is a perennial or a small subshrub. That means it lives for years or forms a small, woody shrub. Plants for a Future gives a height of about 3.3 feet [1 metre]. The source does not say how wide it grows when mature. Each plant has separate male and female flowers. The term for this is monoecious. The sources do not say when it blooms. They give no facts about its fruit. Nor do they give a clear account of leaves or bark. The sap has latex, which poses risks when you handle it.

In gardens, queen's delight can grow in sun or light shade. Light woods are one place that could give such shade. Plants for a Future says it likes moist soil best. It can grow in sand, loam, or clay. These give gardeners a choice of soil types. It also copes with mildly acid, neutral, or mildly alkaline soil. The source lists garden beds as a place to grow it. Its wild sites include sand, but it still prefers moist soil. The sources give no hardiness zone or rate of growth. They name no pests or diseases that affect it. They give no ways to control such problems.

Plants for a Future lists no known food uses. It gives the plant an edibility score of zero. Latex can cause skin blisters. Large doses may cause poisoning. These risks set its old uses as medicine apart from food uses. The source notes past use of root preparations for several complaints. People used them for diarrhoea, vomiting, and poor appetite. They also used them for menstrual problems and venereal disease. These records show past use, not proof that treatment works or is safe. Plants for a Future gives its value as medicine a low score. It lists no other uses. It does not flag a risk of becoming a weed.