Oxalis rubra

Native to southern Brazil, Uruguay and northern Argentina, this perennial herb forms rounded clumps from scaly underground rhizomes. Its leaves have three clover-like leaflets that fold downward at night. Clusters of pink to magenta flowers rise on slender stalks and also close after dark. Hot, dry conditions can trigger dormancy, followed by regrowth when moisture returns. It can be propagated by dividing the rhizomes. The leaves contain oxalates, which can be harmful if large quantities are eaten. Photographed in Colombia.