PlantFiles: Creeping Wood Sorrel
Oxalis corniculata

According to the USF Atlas of Florida Vascular plants, Oxalis corniculata is also native to Florida. I see it in my garden less often than the more invasive, non-native Oxalis violacea.

I agree - I just found out it was different from O. stricta - actually have some purple foliage while O. stricta tend to be strongly green (except in the cultivar which escape from pots with regularity) without any hint of purple in it. It's on my list of impossible to get rid of weeds, it break easily near the soil surface when pulled on so you have to dig deep to get their taproots. Not easy when you consider plants nearby, especially thorny bushes.

A pernicious,noxious weed.

Creeping Wood Sorrel (Oxalis corniculata) is referenced as growing natively in 2 counties of Texas.

The chewed leaves were once used to treat sore throat, nausea and mouth sores. Fresh leaves were poulticed on cancers, old sores and ulcers. Leaf tea was used to treat fevers, urinary infections and scurvey. CAUTION: Large doses may cause oxalate poisoning.

Here in Monterey CA we have a native variety of this plant which has large (1" diameter) yellow flowers in clusters of 3 or 4 blooms. In Zone 11 it blooms in late January with other Spring bulbs such as Irises. In more normal zones (4-8) it would probably be an early Spring bloomer. The effect is quite pretty. It does spread easily, but is also fairly easily controlled by uprooting unwanted plants. It makes a great container or window box plant and is also nice for naturalizing in lawns and meadows. Prefers sandy soil. Needs little water and can be used for xeriscaping. I have found a rare sport of this plant which has double blooms, and would love to share some with other gardeners.

Creeping Woodsorrel is often mistaken for Yellow Woodsorrel (O. stricta). While creeping woodsorrel has a prostrate habit, O. stricta is erect. Though both can have a reddish purple tinge to the leaves, it occurs more often with Creeping Woodsorrel. The most definitive difference is that Creeping Woodsorrel has a slender taproot & spreads by aboveground stolons, while Yellow woodsorrel has underground rhisomes.

O. corniculata spreads by rooting at nods along the prostrate, hairy stems. The foliage is palmate, formed by three inverted, heart-shaped leaflets. The leaflets are creased and fold upward at night or during times of stress. The stems are branched at the base.

Small yellow flowers bloom singly or in clusters from long stems at the leaf axils. Blooms occur from spring to fall. The seed capsule is cylindrical with flat sides and somewhat hairy. When ripe, the seeds are ejected over 10 feet from the plant.

Creeping Woodsorrel is native to Mexico, SW New Mexico, Southern Arizona and Central California. It prefers dry, sandy soil in cleared areas. In cultivated areas it is considered a "weed".