creeping woodsorrel

Scientific name: Oxalis corniculata. Verified common names: creeping woodsorrel, creeping oxalis, procumbent yellow-sorrel, dwarf oxalis. Family: Oxalidaceae. Genus: Oxalis (the wood-sorrels). Taxonomically it is a member of the widespread Oxalis clade of small, sour-tasting herbaceous plants.

Habit: Low-growing, prostrate or trailing herb that typically forms mats or loose patches; stems often root at nodes and can spread across soil or mulch. Plants may behave as annuals or persist as perennials depending on climate.

Flowers: Small, usually yellow, appearing singly or few per stem. Petals typically number 4–6 (most often 5) and are broadly obovate to rounded, giving a simple, open appearance. Flowers may open in daylight and close in low light.

Leaves: Trifoliolate (three leaflets) on slender petioles; each leaflet is generally heart-shaped to obcordate with a smooth margin, giving a clover-like look though unrelated to legumes. Leaflets often fold or angle in response to light conditions.

Distinctive features: Very small yellow flowers combined with clover-like three-part leaves and a mat-forming, node-rooting habit make this species recognizable. Fruits are elongated, cylindrical capsules that can release seeds forcefully when mature.

Seasonal variation: Flowers and active growth often occur during warm months and, in mild climates, may continue year-round. Leaves and flowers may close or droop in cold, dark, or drought conditions.

Growing conditions: Often found in disturbed sites—lawns, garden beds, pavement cracks, open ground, and shaded edges. Tolerates a range of soils from compacted urban soils to richer garden loams and is commonly found in both sun and partial shade. Moisture preference is generalist; plants persist in well-drained to moderately moist conditions.

Geographic distribution: Present across much of the United States, including AL, AR, AZ, CA, CO and many additional states (44 more), and widely naturalized in temperate and tropical regions worldwide.

Pollination: Flowers are visited by small bees, flies, and other small insects and can self-pollinate; insect visitation contributes to pollen transfer in many populations.

Wildlife interactions: Serves as a nectar and pollen resource for small pollinators. Leaves are eaten by some invertebrates; the plant’s low mats can provide microhabitat for tiny ground arthropods.

Ecological niche: Functions as a rapid-colonizer of open, disturbed microhabitats and as a groundcover that can outcompete seedlings in tight spaces.

Conservation status: Not generally considered threatened; often treated as a common weed in managed landscapes.

Interesting facts: The plant’s sour taste comes from oxalic acid, a chemical that gives wood-sorrels their characteristic tang. Its seed capsules may eject seeds when disturbed, a form of ballistic dispersal that helps local spread. The prostrate, node-rooting habit is a key adaptation for rapid vegetative spread across soil and mulch.