large-leaved yarrow

A herbaceous perennial, 40-100cm high, with grey-green stems, woody at the base, leaves covered above and below in fine silvery hairs, giving them a grey-green appearance, flat and lanceolate to broadly ovate in outline, 7–20cm long and 5–10cm wide, deeply pinnatifid to pinnatisect, with 4–6 (sometimes 8) pairs of pinnatifid, cuneate–lanceolate segments, and dense corymbs, 5-20cm across, containing 50-250 flowerheads, each with usually 4-5 white ray florets, in early summer; not to be confused with Tanacetum macrophyllum