Bristly Oxtongue (Helminthotheca echioides)
Bristly oxtongue is a tough, deep-rooted annual or biennial weed that thrives in lawns, pastures, roadsides, and waste areas throughout New Zealand. It grows best in dry, compacted soils and is most noticeable in summer when its coarse, hairy leaves and yellow dandelion-like flowers appear.
It can become a real nuisance in lawns and turf because of its spiny leaf surfaces, which make it unpleasant to walk on and difficult to mow cleanly. In pastures, livestock avoid it due to its coarse, bristly foliage, allowing it to spread and dominate under-grazed or open areas.
Identification
Bristly oxtongue forms a rosette of rough, spiny leaves that feel coarse to touch — similar to sandpaper. The leaves are covered in stiff hairs with small pimples at their base, giving them a blistered appearance. Each leaf is shaped like a spear, with prickles along the edges and a rough midrib.
As the plant matures, it sends up a tall, branching flower stem up to 1 m high. The stem and leaves exude a milky sap when broken. The yellow flowers are similar to dandelion but smaller and appear in clusters on the upper stems from spring through late summer.
After flowering, the plant produces seeds attached to fine, white hairs (pappus), allowing them to disperse easily in the wind. These seeds can remain viable in the soil for years, helping new plants establish even after control.
It can be confused with catsear, hawkbit, or dandelion, but bristly oxtongue leaves are much rougher, and the stem has noticeable pimples with bristles at their base — a key identifying feature.
Why It’s a Problem
In lawns, bristly oxtongue spoils the surface and makes mowing unpleasant. Its deep taproot helps it survive summer droughts, while the spiny foliage deters foot traffic and reduces lawn quality.
In pastures, it competes strongly with grass, particularly under dry or compacted conditions. Because animals avoid grazing it, bristly oxtongue can spread unchecked if not managed early.
Management and Prevention
Cultural control methods:
- Maintain a dense, healthy turf: Overseed thin patches and fertilise regularly to reduce open areas where oxtongue can establish.
- Improve soil condition: Aerate compacted ground and avoid overgrazing or mowing too low, which encourages weeds.
- Remove flower heads early: Mow or hand-pull before the plant sets seed to prevent further spread.
- Encourage good drainage: It grows aggressively in poorly drained, compacted areas.
Chemical Control:
Bristly oxtongue is relatively tolerant to many common herbicides once mature, so early treatment is best — ideally when the plant is still in the rosette stage.
Effective herbicide options include:
- MCPA (Cleansweep, Soft Touch) – most effective when applied to young, actively growing plants.
- 2,4-D/dicamba mixtures – suitable for lawns and pastures; apply in spring before flowering.
- Triclopyr/picloram mixtures (NZLA Gold) – strong control of mature plants but may damage clover, so not suitable for all pastures.
- Glyphosate – effective for spot-spraying or total vegetation control in waste areas, but will kill surrounding grass.
Repeat applications may be necessary three to six weeks apart for full control, especially if plants have already begun to flower.