Yarrow is a common herb that has been highly regarded for its medicinal properties in Britain since Anglo-Saxon times (4). The erect stems are woolly and the dense, flattened flower-heads are typically white, but more rarely they may be pink or reddish (2). The leaves are deeply divided, forming many small lobes (5); this feature is referred to by the specific Latin name, millefolium, which means 'thousand leaf' (6). The name of the genus, Achillea is thought to have arisen as it is said that Achilles used this herb to treat the wounds of his soldiers. The common name 'yarrow' derives from the Anglo-Saxon name for the plant, 'gearwe' (7).