Oxalis perennans
woody-root woodsorrel
Overview
Oxalis perennans is a low, spreading perennial herb 5-30 cm (2-12 in) tall, growing from a woody taproot and rootstock that sets it apart from bulb-forming relatives. The leaves are clover-like, divided into three heart-shaped leaflets each 5-15 mm (0.2-0.6 in) wide, that fold down at night and in bright sun. Small five-petalled yellow flowers about 5-10 mm (0.2-0.4 in) across open over much of the year, mainly in the warmer months, and are followed by narrow cylindrical capsules that split to fling out seed. It is native across much of Australia and grows in grassland, open woodland, lawns, gardens, and disturbed ground on a wide range of soils. The plant spreads by seed and from the persistent rootstock, so it can become a weed of lawns and beds, and the foliage contains oxalic acid, which gives it a sour taste and makes large quantities unsafe to eat.
Native Range
Native to Australia, where it is widespread across all states in grassland, woodland, and disturbed ground. It also occurs as a naturalised plant in New Zealand.Suggested Uses
Grown occasionally as a low groundcover or in native and habitat plantings for its long flowering and insect value. In lawns and beds it is more often managed as a spreading weed than cultivated. The trifoliate foliage and yellow flowers also feature in informal native ground layers.How to Identify
Appearance
Size & Dimensions
Height2" - 1'
Width/Spread6" - 1'4"
Bloom Information
Small yellow five-petalled flowers open over much of the year, with the heaviest flowering in the warmer months. The flowers attract small bees and other insects. Narrow cylindrical capsules follow and split open to fling seed several centimetres from the plant.
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Requires 4-9 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
Care & Maintenance
Care Guide
Grows in full sun to part shade on almost any free-draining soil across a pH range of about 5.0-7.5. It is drought-hardy once established, resprouting from the woody rootstock after dry spells or mowing. Rich, moist soils encourage faster spread. The plant self-seeds and regrows readily, so it persists once present and can move into lawns and beds. It tolerates light frost, with foliage dying back in cold conditions. Removing the whole rootstock is needed to stop regrowth, as broken pieces resprout.Pruning
Cutting or mowing reduces the foliage but does not remove the woody rootstock, from which the plant regrows. Removing seed capsules before they ripen limits self-seeding. Hand-removal of the entire rootstock is the most thorough way to control spread.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons