Asclepias

from WordNet (r) 3.0 (2006)

Asclepias
    n 1: genus of chiefly North American perennial herbs: silkweed;
         milkweed [syn: {Asclepias}, {genus Asclepias}]

from The Collaborative International Dictionary of English v.0.48

Asclepias \As*cle"pi*as\, n. [L., fr. Gr. ?, named from
   Asclepios or Aesculapius.] (Bot.)
   A genus of plants including the milkweed, swallowwort, and
   some other species having medicinal properties.
   [1913 Webster]

   {Asclepias butterfly} (Zool.), a large, handsome, red and
      black butterfly ({Danais Archippus}), found in both
      hemispheres. It feeds on plants of the genus Asclepias.
      [1913 Webster]