Oxalis pes-caprae L.
A hairless, tufted herbaceous perennial. Leaves mainly basal, trifoliate, on petioles up to 20 cm long. Leaflets obcordate, emarginate, 5 to 40 mm long. Flowers bright yellow, about 3 cm across, in umbels of 6 to 12 flowers. Scapes to about 30 cm. Flowers sometimes appear with more than the usual 5 petals. These are much less common. They are smaller than normal and often tinged reddish-purple.
Local: Very common and widespread throughout Gibraltar.
Global: A native of south Africa, it has been introduced and become naturalised. Found throughout the Mediterranean region and Portugal, and has become a serious weed in vineyards, olive groves, etc.
Flowers between (December) January, February, March, April and May.
Grows in clearings and waysides; open ground.