Yarrow Achillea millefolium
Yarrow is a perennial weed, common weed on all types of lawns and turf in the UK. It has deep fibrous roots and can withstand droughty conditions. It spreads by creeping stems which root at intervals. It is generally seen later in the year and the deep root system also gives it the benefit of being able to survive dry conditions. The leaves are fern like in appearance macking it very easy to identify.