Oxalis latifolia aka Broadleaf Woodsorrel

Oxalis latifolia, or garden pink sorrel, belongs to Oxalidaceae. It comes from tropical and subtropical parts of the Americas. It grows in humid tropical regions and the subtropics. It has also spread into warmer temperate regions as a weed. Gardeners grow it for its leaves and pink flowers.

This bulbous perennial forms clumps and can spread into carpets. Descriptions put its leafy growth at 0.7–1 foot [0.2–0.3 metres]. The RHS size table gives a higher range: 1.6–3.3 feet [0.5–1 metre]. Its listed spread reaches 1.6 feet [0.5 metres]. The mid-green leaves each have three leaflets with fishtail-like tips. The plant sheds its leaves rather than keeping them year-round. Small groups of pink flowers open in summer. Insects pollinate the flowers, and plants can also self-seed.

Below ground, it has a scaly bulb and several root types. These include fleshy storage roots, fibrous roots, and rhizomes. Underground stolons can form many new bulbs at their tips. Some forms make new bulbs close to the parent instead. Each new bulb can produce another leafy clump. Moving or disturbing soil helps spread these small bulbs. This makes the plant hard to contain once established.

Grow it in sun or partial shade, in a sheltered spot. The RHS lists chalk, loam, and sand as suitable soils. It accepts acid, neutral, and alkaline conditions. Soil should drain well, with moisture available during growth. The RHS gives it a UK hardiness rating of H5. Plants take two to five years to reach full size. Containers help limit its spread, and it can grow indoors. In tropical gardens, people also use it as ground cover. It needs no pruning. Slugs and snails may attack outdoor plants; rust can also occur. Its value as an ornamental comes with serious weed risks. It troubles farms and plant nurseries in many countries.

In Mexico, people use the leaves and stems as food or tea. The leaves also serve as a pickle ingredient. Their sour taste comes from oxalic acid. Large amounts can reduce the calcium available to the body. Cooking lowers the oxalic acid content but does not remove the warning. People with kidney stones, gout, or related conditions need extra caution. Another recorded use mixes the root with natural dyes. This helps the dye hold its colour.