Rumex scutatus aka French Sorrel

Rumex scutatus is known as French sorrel. It also goes by the name buckler-shaped sorrel. It is an herbaceous perennial: a non-woody plant that lives for years. It belongs to the buckwheat family, Polygonaceae. Its native range spans Europe, southwest Siberia, and Iran. It grows in places with a temperate climate. These sites include old walls and mountain pastures. People have brought it to Great Britain and Sweden. Gardeners grow it for leaves to eat and spreading cover.

The plant forms low clumps that creep into mats. Garden heights range from about 0.3–2 feet [0.1–0.6 metres]. Published garden spreads range from 1.3–5 feet [0.4–1.5 metres]. The RHS gives a wider spread than NC State. It grows at a moderate rate. Plants take two to five years to mature. Most grey-green leaves grow at the base. Each simple leaf has one blade, with no hairs. The leaves have a spear or spoon shape. The plant sheds its leaves instead of keeping them year-round.

Small green or red flowers grow on upright racemes. These are stalks with flowers spaced along them. Chicago Botanic Garden records blooms from May through August. Each flower measures less than one inch across. The reddish-brown fruits have three sides, like a triangle. Plants can seed themselves if gardeners leave the flowers intact. Cutting off flower stalks helps the plant grow more leaves. Cut young leaves, then pick more as new growth returns. Caterpillars also feed on this plant.

French sorrel grows in full sun or partial shade. It prefers moist soil that drains well. Rich, fertile ground suits it, but poorer soils can work. It accepts sand, loam, clay, and chalk. It tolerates acid, neutral, and alkaline soil too. Once plants take hold, they withstand drought, frost, and wind. They do not withstand sea salt. Published USDA ranges span zones 4–9. The RHS rates it H6. Grow it in pots, small groups, or cottage gardens. It can also serve as ground cover. It needs little care and has few disease problems. Slugs and aphids may still attack it.

The leaves give food a tart, lemon-like taste. Eat small amounts raw, or cook them in soups and sauces. Older leaves may taste bitter later in the season. Oxalic acid makes large servings unsafe. It can also affect how the body takes up calcium. Cooking lowers the amount of oxalic acid. People prone to kidney stones, gout, or arthritis should take care. Records also note use of the leaves as medicine. Such use is rare. Soluble oxalates can poison dogs, cats, and horses. Small exposures may upset the gut. Large amounts or repeated intake can cause more serious harm.