Oxalis dillenii
slender yellow woodsorrel
Overview
Oxalis dillenii is a low perennial 4-12 inches (10-30 cm) tall, growing from a slender taproot and spreading by short rhizomes and rooting stems. The stems and leaves are covered in short grayish hairs that lie flat against the surface. Leaves are clover-like, divided into three heart-shaped leaflets that fold down at night and in strong sun. Five-petaled yellow flowers about 0.3-0.5 inch (8-13 mm) wide open in small clusters from April through October. Slender, upright, five-sided seed capsules 0.4-1 inch (1-2.5 cm) long follow and split explosively, flinging seeds up to several feet from the plant. The foliage has a sharp, sour taste from oxalic acid. Plants form loose colonies in lawns, gardens, and disturbed ground, where the combination of rhizomes and forcibly ejected seed makes them persistent. Leaves and stems are grayish-green rather than the deep green of related species, and the seed stalks bend sharply downward before the capsules point upward.
Native Range
Native to North America, found across much of the United States, southern Canada, and northern Mexico. Grows in open woods, prairies, lawns, gardens, fields, and roadsides, often on dry, disturbed soils from sea level to about 6,000 feet (1,830 m).Suggested Uses
Rarely planted deliberately; it occurs mostly as a volunteer weed of lawns, gardens, and containers. The sour leaves and flowers are edible in small amounts as a tart garnish. It has little managed garden use and is generally controlled rather than grown.How to Identify
Appearance
Size & Dimensions
Height4" - 1'
Width/Spread6" - 1'
Colors
Bloom Information
Flowers from April through October across most of its range, with the heaviest bloom in late spring and again in early fall. The yellow flowers are insect-pollinated and self-fertile, opening only in daylight. Capsules ripen quickly and eject seed throughout the long season.
Detailed Descriptions
Foliage Description
grayish-greenGrowing Conditions
Sun Requirements
Requires 4-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight