Yellow Wood Sorrel

(Oxalis stricta)

Yellow Wood Sorrel (Oxalis stricta L.)

Identification: Plant erect. Flowers yellow, with 5 petals in an open rosette. Seedpods elongate, borne on long pedicels, the pedicels commonly, but not always, bent. Seedpods, when ripe, explosively opening when touched, spraying the seeds. Leaves with the astringent flavor of oxalic acid. Leaves, green, cloverlike with three lobes, the lobes each with an apical notch and a fold line through the center. Stipules at the base of the leaf petioles small to absent. Leaves may be marked with purple. Plant 6 inches to 2 feet in height.

Distribution: Throughout North America.

Habitat: Yellow Wood Sorrel is found just about everywhere from forest to disturbed habitats of all sorts.

Flowering period: May to October.

Similar Species: Yellow Wood Sorrel is most difficult to separate from Creeping Wood Sorrel. The leaf and flower stalks of Creeping Wood Sorrel arise from a recumbent, trailing stem. Yellow Wood Sorrel is usually a more erect plant. Creeping Wood Sorrel has distinct stipules at the base of the leaf petioles. These stipules are usually absent in Yellow Wood Sorrel. Large Yellow Wood Sorrel is much like Yellow Wood Sorrel, but larger. The flowers are up to 1 inch in diameter. The flowers of Yellow Wood Sorrel are usually about one-half that size. The leaves of Large Wood Yellow Wood Sorrel are commonly margined with purple. The leaves of Yellow Wood Sorrel may have purple blotches on them, but not along the margins. The flower stalks and stems of Large Wood Sorrel are bristly. The flower stalks of Yellow Wood Sorrel are smooth or just slightly hairy. The seedpods of Yellow Wood Sorrel are elongate, but those of Large Yellow Wood Sorrel are relatively short and stubby.

Comments: Yellow Woodland Sorrel is an extremely variable species in both morphology and habitat. Several names have been applied to the variants including rufa, europaea, filipes, and florida. Although sometimes treated as separate species, these names are now all considered to by synonyms of stricta.