Any broken part of milkweeds wards off herbivores via a poisonous latex that it exudes.


"Milkweed gets its name from a poisonous latex that exudes from its broken stem. This is so toxic that it can give a small animal a heart attack." (Attenborough 1995:70-71)

The Private Life of PlantsBBC BooksFebruary 23, 2017
David Attenborough