pyrethrum parthenium

from The Collaborative International Dictionary of English v.0.48

Feverfew \Fe"ver*few\ (f[=e]"v[~e]r*f[=u]), n. [AS. feferfuge,
   fr. L. febrifugia. See {fever}, {Fugitive}, and cf.
   {Febrifuge}.] (Bot.)
   A perennial plant ({Pyrethrum Parthenium}, or {Chrysanthemum
   Parthenium}) allied to camomile, having finely divided leaves
   and white blossoms; -- so named from its supposed febrifugal
   qualities.
   [1913 Webster]