swallowwort

noun

• 1a plant of the milkweed family, the follicles of which suggest a swallow with outstretched wings, often becoming a weed.

  • Several species in the family Asclepiadaceae, in particular the black swallowwort (Cynanchum (or Vincetoxicum) nigrum)

• 2chiefly British the greater celandine, formerly believed to be used by swallows to restore their sight.