Leave a bit, and you'll have 1,000 more. White clover is a low-growing perennial. Compound leaves sport three leaflets marked with white, and they aren't lucky. It does produce nice little globe-shaped white flowers in spring, but those clumps just get bigger and bigger, thanks to creeping stems that happily root at nodes. If you get it, your turf grass may scream because the clover may win.
Clumps pull fairly easy in moist or loose soil, but some people resort to herbicides.
Fond of cool weather, it reproduces with underground bulbs, aerial bulbils and seed. Leaves are round and hollow. Some people like the scent, mixed with that of cut grass, when they mow the lawn. Imported cabbageworm is a velvety green caterpillar sporting a thin yellow stripe down its back. Big ragged holes in leaves are a clue.