Yellow Wood Sorrel

Oxalis stricta

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Photo of yellow wood sorrel plant showing flowers and leaves.
Yellow wood sorrel is a familiar native plant. It occurs throughout North America and has been introduced widely in the Old World.
James H. Miller & Ted Bodner, Southern Weed Science Society, Bugwood.org
Edible
Other Common Name
Sheep Sorrel; Sourgrass; Common Yellow Woodsorrel
Family

Oxalidaceae (wood sorrels)

Description

Yellow wood sorrel is an herbaceous annual or perennial with taproots when young, developing rhizomes with age. Flowers in unevenly branched panicles on long stems, with 5 yellow, rounded petals. Blooms May–October. Leaves alternate, trifoliate (like clover), the leaflets heart-shaped, light to dark green or copper to purple, often recurved, sometimes with grayish hairs. At the end of each day, the leaflets droop or fold downward, parallel to the stem; they spread again the next morning. Fruit an upright, pointed capsule to about 1 inch long.

Similar species: There are 5 species of Oxalis in Missouri. One is violet wood sorrel, with pink or violet flowers. The other 4 all have yellow flowers. Of these, O. stricta is the tallest, most common, and the only one with flowers in panicles (a central flower flanked by a pair of branches bearing 2 or more flowers). The rest have the flower stalks umbellate (arising from the same point at the tip of a stem).

Size

Height: 4 to 20 inches, occasionally to 3 feet.

yellow_wood_sorrel_lawn_7-7-14.jpg

Photo of yellow wood sorrel plant growing in a lawn.
Yellow Wood Sorrel
Yellow wood sorrel is both garden weed and wild edible. It has a pleasant sour taste, which is why some people call it sourgrass.

yellow_wood_sorrel_plant_7-7-14.jpg

Photo of yellow wood sorrel plant on a blue background.
Yellow Wood Sorrel
Of Missouri’s four yellow-flowering oxalis species, yellow wood sorrel (O. stricta) is the tallest and most common.

yellow_wood_sorrel_wood_7-7-14.jpg

Photo of yellow wood sorrel plant with a piece of wood in the background.
Yellow Wood Sorrel
At the end of each day, the leaflets of yellow wood sorrel droop downward, parallel to the stem; they spread again the next morning.
Habitat and conservation

Found nearly everywhere. Occurs in bottomland and upland forests, savannas, upland prairies, glades, banks of streams and rivers, pastures, fields, gardens, railroads, roadsides, and other disturbed areas. Various species of oxalis are hosts in the complex life cycles of rusts that afflict corn, sorghum, and other crop grasses.

image of Yellow Wood Sorrel Sheep Sorrel Distribution Map
Distribution in Missouri

Scattered statewide. This native plant occurs throughout North America and has been introduced widely in the Old World.

Human connections

This plant is both garden weed and wild edible. It has a pleasant sour taste, which is why some people call it sourgrass or lemon clover. Nibble on it as you work in your garden, or add it to salads. Note that, like spinach and rhubarb, the oxalic acid in the plant makes it toxic if eaten in very large quantities.

Ecosystem connections

Like other weedy plants, yellow wood sorrel colonizes disturbed soils and begins the revegetation process. A host of animals, ranging from insects to birds to rabbits and deer, eat this plant. Bobwhite, sparrows, and other birds eat the seeds. Many insects visit the flowers for pollen and nectar.