noun
1. : a plant that yields indigo: as
a. : any of several plants of the genus Indigofera (as I. tinctoria of Africa and India, I. anil of So. America, I. auriculata of Arabia and Egypt)
b. : an East Indian woody vine ( Marsdenia tinctoria ) that yields rank indigo
c. : an Asiatic herb ( Polygonum tinctorium )
2.
a. : an Australian plant (as the Darling pea) of the genus Swainsona
b. : box brier