The Acaena is found mainly in the South America, New Zealand and Australia. The leaves are alternate, 4-15 cm long, and pinnate or nearly so, with 7-21 leaflets. The flowers are produced in a tight globose inflorescence 1-2 cm diameter, with no petals.

The Acanea fruit is a dense ball of many seeds; in many (but not all) species the seeds bear a barbed arrowhead point, the seedhead forming a burr which attaches itself to animal fur or feathers for dispersal.

Acaena species were introduced into cultivation in Northern Ireland from New Zealand for use mainly as rockery plants. Acaena ovalifolia is the commonest species to be found as an escape in wild situations, mainly in forestry plantations, demesnes and woodland. It is fast-growing and spreads readily by creeping over the ground and also by seed. The globular flower-heads are followed by spiny fruits which attach themselves easily to animal fur or human clothing.

It is now illegal to plant Acaena plants in the wild in Northern Ireland because of the damage their spread could do to native vegetation.

Some of the species of Acacia include the Acaena anserinifolia, Acaena argentea, Acaena buchananii, Acaena caesiiglauca, Acaena exigua – Liliwai, Acaena fissistipula, Acaena inermis, Acaena laevigata, Acaena lucida, Acaena magellanica, Acaena microphylla
 
Did you know?
 
The Acaena Pinnatifida is a Ferny creeping plant. It has tight spikes of small creamy flowers with black middles. It grows well in May-Jun and has ferny foliage of 25cm.
Acaena is a genus of about 100 species.   
Acanea needs well drained soil.