Bermuda buttercup (Buttercup oxalis)  (Oxalis pes-caprae)

Bermuda buttercup (buttercup oxalis), a low growing perennial broadleaf plant with shamrocklike leaves, is found throughout California up to 8200 feet (2500 m). It inhabits agricultural land and other disturbed areas and is a common weed in artichoke fields on the Central Coast and in irrigated landscapes. It is related to, and closely resembles, creeping woodsorrel, Oxalis corniculata. Both species contain variable levels of oxalate compounds that can cause death in livestock when consumed in large quantity. They are attractive but are a nuisance when they spread into gardens or when they infest shrubs. Sometimes Bermuda buttercup is grown as an ornamental.

Habitat

Orchards, vineyards, crop fields, grassland, yards, gardens, turf, landscaped areas, and urban areas.

Seedling

Seedlings are not encountered in California.

Mature plant

A loose basal rosette of leaves up to about 14 inches (35 cm) tall grows from the bulb. It has fully subdivided (compound) leaves, each consisting of three heart-shaped leaflets that resemble clover leaves. Leaves are hairless to sparsely hairy, green, often with brown or purplish spots. Stems are located mostly below ground. It can be distinguished from creeping woodsorrel by its more upright growth, larger leaves and flowers, greater number of flowers, and lack of seed capsule.

Flowers

Flowers bloom from November through April. Flowers cluster on the ends of slender leafless stalks and there are less than 20 flowers per cluster. Each flower has 5 bright yellow petals.

Reproduction

Reproduces by bulbs and bulbets. Cultivation, soil movement, planting, and the disposal of nursery soil and garden waste disperse bulbs and bulbets.

Related or similar plants

• Creeping woodsorrel, Oxalis corniculata

More information

• Broadleaf ID illustration
• Calflora's distribution map
• For agriculture: UC IPM Pest Management Guidelines
• For gardens and landscapes: UC IPM Creeping Woodsorrel and Bermuda Buttercup Pest Note