in botany, a genus of plants belonging to the genyphila polygamia superflua clas. Of this genus there are 21 species, only two of which are natives of Britain, viz. the achillea millefolium, or common yarrow, (see Plate II. fig. 1.) and the achillea ptarmica, or sneezewort.

a name frequently given by the ancients to the gum called dragons blood. See **Dragons-blood**.