Feverfew; a genus of the polygama superflua order, belonging to the syngenesia class of plants. There are five species, but the only remarkable one is the parthenium or common feverfew. This hath very fibrous clustering roots, crowned with numerous compound leaves; upright stalks branching on every side two or three feet high; garnished with compound plain leaves of seven oval folioles, cut into many parts; and all the branches terminated by many compound radiated white flowers having a yellow disc. There are varieties with double flowers, with semi-double flowers, with double filarial flowers, with a filarial disc and plain radius, with short-eyed flowers, with rayless flowers, with rayless sulphur-coloured heads, and with finely curled leaves.—All these varieties flower abundantly in June, each flower being composed of numerous hermaphrodite and female florets; the former compose the disc, the latter the radius or border, and which, in the double and filarious kinds, are very ornamental in gardens, but of a disagreeable odour; and are all succeeded by plenty of seed in autumn, by which they are easily propagated, as well as by parting the roots and cuttings.

Medical uses. This plant has received a most extraordinary character in hysteric and other affections of the nerves, as well as for being a carminative, or warm stimulating bitter. Dr Lewis, however, thinks it inferior to camomile; with which he says it agrees in all its sensible qualities, only being somewhat weaker.