|O. variabilis has large black egg-shaped bulb, and rounded leaves which have purple undersides. Blooms in large purple flowers with a yellow tube.
Oxalidaceae is a genus of about 800 species. Many are tuberous, the leaves are usually three-lobed and clover-like. Both the leaves and flowers close up in dull weather and at night. May be used about the rock garden, planted in sunny corners or in a trough.