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":Vincetoxicum hirundinaria
Any of several vines of the genus Cynanchum, especially black swallowwort (Cynanchum nigrum) or white swallowwort (Cynanchum vincetoxicum). Cynanchum is from Greek words meaning "to choke a dog."
Greater Celandine (Chelidonium majus).
Greater Celandine and Swallowwort were each often categorized with Tetterworts because they were used to treat Tetter. This led to nomenclature confusion among these worts.
many plants of the genus Asclepias
Seutera angustifolia, a plant of the genus Seutera