Any of several plants of the family Fabaceae (Leguminosae) having inflated seed pods that rattle when dry; especially the West Indian Crotalaria incana and wild indigo, Baptisia tinctoria.
Origin
Mid 18th century; earliest use found in Griffith Hughes (1707–1750).
Definition of rattle bush in US English:
rattle bush
noun
Any of several plants of the family Fabaceae (Leguminosae) having inflated seed pods that rattle when dry; especially the West Indian Crotalaria incana and wild indigo, Baptisia tinctoria.
Origin
Mid 18th century; earliest use found in Griffith Hughes (1707–1750).