PlantFiles: New Zealand Bur, Buzzy, Bidgee-Widgee
Acaena novae-zelandiae

This is not a plant you'd want to plant anywhere clothes or pets would come into regular contact with it. The hooks on the seed heads are incredibly efficient. But I needed something for the top of a bank, at the foot of a fence, inaccessible to everyone and where watering was impossible ( even when we are allowed to do so) and the local bush regeneration nursery suggested it. It is a local plant and fed on by a number of local butterflies, but rarely planted. It's done a brilliant job, each plant has covered several square feet since planting in the Spring, with only the one watering at planting. We haven't had any rain for 3 weeks, several of the days since then have been over 100C and it's a lush green still when most plantsin my garded are suffering some stress and showing it..

This plant is famous in Australia as the first major weed that Australia has contributed to the rest of the world!
The fruit are spheres of achenes, each with a hooked awn and the individual seeds easily attach themselves to your clothing and are spread far and wide. They are native in this area, but still a great nuisance.

Also known as "biddy biddy", though I have yet to determine why. :) This plant is not native to the U.S. Groundcover.