Source : Webster's Revised Unabridged Dictionary (1913)

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.

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

Source : WordNet®

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