
1) Asclepias curassavica 2) Blood flower 3) Milkweed 4) Silkweed
Found on
https://www.crosswordclues.com/clue/swallowwort

Swallowwort or Swallow-wort is a term used for several plants and plant families. While the term `Swallowwort` may be derived from description of poisonous effects; there were, in the past plants used medicinally for tonsillitis and referred to as `swallowwort`. The following plants are referred to as `Swallowwort`: ...
Found on
http://en.wikipedia.org/wiki/Swallowwort

• (n.) A poisonous plant (Vincetoxicum officinale) of the Milkweed family, at one time used in medicine; -- also called white swallowwort. • (n.) See Celandine.
Found on
http://thinkexist.com/dictionary/meaning/swallowwort/

Swal'low·wort` noun (Botany) (a) See Celandine . (b) A poisonous plant ( Vincetoxicum officinale ) of the Milkweed family, at one time used in medicine; -- also called white swallowwort . African swallowwort , a plant of the genus Stapelia.
Found on
http://www.encyclo.co.uk/webster/S/255

celandine (def. 1). · any of several plants of the milkweed family, esp. a climbing vine, Cynanchum nigrumnative to Europe, having small, brownish flowers.
Found on
https://www.infoplease.com/dictionary/swallowwort
No exact match found.