Mind-your-own-business (MYOB) is a semi-evergreen perennial related to the Common Stinging Nettle, which forms a dense mat about 5cm high. Originally introduced as an ornamental plant, from Corsica, it is now widespread in the British Isles and is usually regarded as a pestilent weed due to its creeping habit and an ability to resist destruction. Small fragments of the stem can take root.

In the right place it makes excellent ground cover and is grown indoors as well; there are yellow- and whitish-leaved varieties. It prefers moist soil and partial shade, spreading rapidly using pink thread-like stems. The foliage is killed by frost, but it regrows in the spring.
The round, bright green leaves have bristly hairs. The pink-tinged, white flowers are about 1mm in diameter and appear from May to October.
Scrape off the mat and try to remove all of the fragments. A deep mulch over the area should kill any missed pieces. It is very difficult to remove from the lawn by cultural methods. Try raking it out, but be careful not to spread it to unaffected areas. Then feed the grass and allow it to grow longer for a while to out-compete the MYOB. A tight, strong-growing sward should win in the end!
It is resistant to selective weedkillers used for treating the lawn, it may be nesessary to kill the grass as well using Glyphosate and resow or patch in some turf when the MYOB has gone. Crushing the tissues by trampling it will increase the uptake of the herbicide. or

Follow these links for further details on Weeds, Weed Removal and Weed Prevention.