swallowwort

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. See celandine.
2. n. Any of several vines of the genus Cynanchum, especially C. nigrum, native to Europe, having clusters of small brownish-purple flowers.

Century Dictionary and Cyclopedia

1. n. The European herb Cynanchum (Asclepias) Vincetoxicum, or white swallowwort, the plant anciently called asclepias. Also called vincetoxicum (which see) and tame-poison.
2. n. Hence, as a book-name, any plant of the genus Asclepias, the milkweed: applied also to the soma-plant, as formerly classed in Asclepias, and to an umbellifer, Elæoselinum (Thapsia) Asclepium, perhaps from its external resemblance to an asclepiad.
3. n. The celandine, Chelidonium majus, once fancied to be used by swallows as a sight-restorer. Compare swallow-stone.

Wiktionary

1. n. Any of several vines of the genus Cynanchum.
2. n. A tetterwort, Chelidonium majus or Sanguinaria canadensis.
3. n. Any of various plants of the genus Asclepias.
4. n. The plant Euphorbia maculata.

GNU Webster's 1913

1. n. See celandine.
2. n. A poisonous plant (Vincetoxicum officinale) of the Milkweed family, at one time used in medicine; -- also called white swallowwort.

WordNet 3.0

1. n. perennial herb with branched woody stock and bright yellow flowers
2. n. tropical herb having orange-red flowers followed by pods suggesting a swallow with outspread wings; a weed throughout the tropics
3. n. perennial herb with branched woody stock and bright yellow flowers