Oxalis violacea L.

Violet Wood Sorrel

© SRTurner

Family - Oxalidaceae

Habit - Perennial forb, with scaly, ovoid, brown or pinkish-tinged bulbs, occasionally with inconspicuous stolons.

Stems - Aerial stems absent.

	Bulb.
© SRTurner

Leaves - Basal, long-petiolate. Petioles glabrous to densely pubescent, with stipules near the base as inconspicuous, translucent wings of tissue. Leaves palmately trifoliate. Leaflets to 20 mm long, broadly obcordate, apical notched to 1/3 of the total length, the upper surface glabrous, green and often reddish- to purplish markings, the undersurface glabrous or sparsely pubescent, green but usually mottled to strongly tinged with purplish red, the leaflet base sometimes with scattered, stiff, unicellular, nonglandular hairs.

	Leaves.
© SRTurner

	Leaf petioles
© SRTurner

Inflorescence - Umbellate clusters of 4-16 flowers, arising from bulb.

	Inflorescence.
© SRTurner

Flowers - Sepals 4-6 mm long, oblong-lanceolate, usually with 2 bright orange thickenings (concentrations of oxalate crystals) at the tip. Petals 9-20 mm long, pink, violet, or purple, rarely white. Corollas often with greenish throats.

	Flowers.
© SRTurner

© SRTurner

Fruits - Fruits 4-6 mm long, oblong-ellipsoid, glabrous. Seeds 1.0-1.5 mm long, brown, the surface somewhat wrinkled or with a faint network of ridges.

	Fruits.
© SRTurner

Flowering - March - May, again in September - November.

Habitat - Forest openings, savannas, glades, prairies, pastures.

Origin - Native to the U.S.

Lookalikes - None.

Other info. - This attractive species can be found throughout most of Missouri, as well as across the eastern half of the continental U.S. The plant is easy to identify because of its bulb-like stem, three-parted leaves (often with purplish markings), and its pink flowers.

The genus name Oxalis apparently derives from the Greek "oxys" meaning "sharp," referring to the sharply sour taste of the leaves. The pleasant tartness is due to the plant's content of oxalic acid, a substance also found in several other foods as well as rust remover. Oxalic acid is toxic if consumed in quantity due to formation of calcium oxalate crystals in the kidneys, and the usual advice is to avoid eating large quantities of foods which contain it. Except for people with kidney disease, ingesting a toxic dose from consuming a reasonably quantity of sorrel leaves is unlikely, and they are often used to lend a sour accent to salads and the like. The tree Averrhoa carambola, which produces the fruit known as carambola or "star fruit," is also a member of the Oxalidaceae. These fruits should also be eaten in moderation.

O. violacea is unusual in that the plants often bloom a second time, in the fall, in addition to the normal spring flowering. These late blooms often appear without any leaves being present.

Photographs taken at Shaw Nature Reserve, Franklin County, MO, 4-22-2007, Engelmann Woods Natural Area, Franklin County, MO, 4-12-2010 and 4-19-2014, Glassberg Conservation Area, Jefferson County, MO, 4-04-2016, Danville Conservation Area, Montgomery County, MO, 5-15-2018, and along the Katy Trail near Dutzow, Warren County, MO, 4-22-2022 (SRTurner).