Oxalis violacea aka Violet Woodsorrel

Oxalis violacea, or violet wood sorrel, belongs to the Oxalidaceae family. It grows wild across the central and eastern United States. Its native range also reaches northern Mexico. People have introduced it to some western states and Puerto Rico. This small perennial grows in woods, prairies, and rocky ground. It also occurs along river banks and on shaded slopes.

Plants reach about 0.33–0.75 feet [0.10–0.23 metres] tall. Their spread can reach 0.75 feet [0.23 metres]. Leaves and flower stalks rise straight from a buried bulb. The bulb has a coat of scales. Each leaf has three green leaflets that look like hearts upside down. Their edges are smooth, and both sides lack hairs. The undersides may have a purple tint. Cold weather or strong sun can turn leaves purple. The leaves open during the day.

Flowers stand above the leaves on bare stalks. Each umbel holds two to five flowers. Only one or two may open at once. Each small flower has five petals and a pale, greenish throat. Pink and lavender are usual colors, though white and violet also occur. Bloom falls in May to June, with some fall flowers. Cooler fall weather can bring this second flush. Slender, pointed fruit capsules hold light brown seeds. Each capsule splits into five parts and may throw seeds outward.

Grow violet wood sorrel in sun or partial shade. It does best in soil that drains well. It accepts clay, loam, sand, and shallow rocky soils. Acidic to neutral soil suits it. Give it moderate moisture, though it tolerates some dry spells. Sources place it in USDA zones 5–9. Plant bulbs in fall for flowers the next year. Division and seed offer other ways to grow it. Runners from the bulbs can spread fast and form colonies. This makes it useful as ground cover or in naturalized sites. It also suits rock gardens, native gardens, and border fronts. Bees visit the flowers. Sources report no serious pest or disease problems.

Leaves, flowers, and roots have recorded food uses. Leaves and roots can be eaten raw or cooked. Raw flowers can garnish salads. Use only small amounts because the leaves contain oxalic acid. Cooking lowers the amount but does not remove every concern. Large servings can reduce the body's supply of calcium. People with kidney stones, gout, or arthritis need caution. All parts have toxic potential, and pets and livestock face risks.