Oxalis violacea L.

Violet Wood Sorrel

Oxalis violacea plant

Family - Oxalidaceae

Stems - Absent. Scaly bulb present below ground.

Leaves - Basal, trifoliolate, petiolate. Petioles to +10cm long, purplish, glabrous to pubescent. Leaflets sessile, obcordate, to +2cm long, +2.5cm broad, glabrous to sparse pubescent, entire, deep green to purplish-green above, purple below.

Oxalis violacea leafLeaf-note the purple under-side.

Inflorescence - Scapose umbels of +10 flowers arising from bulb. Scapes to +15cm tall, erect, longer than the leaves, whitish-green or with a pinkish tinge, glabrous to pubescent. Ray of umbel (pedicels) to +1cm long, glabrous or sparse pubescent.

Flowers - Petals 5, joined at base, purplish, with yellow and green at base, to 2cm long, 7mm broad, obtuse to truncate at apex, glabrous. Stamens 10, two sets of different sizes. Filaments connected at base. Anthers yellow. Pistil 5-carpellate. Styles 5. Sepals 5, greenish, subulate, to +5mm long, with orange mass(callosity) at apex, entire, typically glabrous. Capsule to 6mm long, elastically dehiscing from vertical sutures.

Oxalis violacea calyxCalyx.

Oxalis violacea flower

Flowering - April - July and often again in the fall.

Habitat - Rocky open woods, glades, prairies, roadsides.

Origin - Native to U.S.

Other info. - This is a common plant throughout the state. It forms large colonies where conditions are favorable. Steyermark lists two varieties for the plant based on pubescence. Variety tirchophora Fassett has gland tipped hairs on the petioles. Variety violacea has petioles which are glabrous. A white flowered plant is O. violacea var. violacea f. albida Fassett.
Many people, like my dad, eat Oxalis. This can be bad because the plant contains oxalic acid which is secreted as calcium oxalate crystals. These crystals can give the plant a glaucous appearance. The sharp, jagged crystals botch your kidneys if ingested in large quantity, so eat the plant with moderation. Averrhoa carambola L. or "Star Fruit" is a member of the Oxalidaceae, and should also be eaten in moderation.

Photographs taken at Danville Conservation Area, Montgomery County, MO., 4-8-04.