bastard indigo vs Tephrosia purpurea

bastard indigo and Tephrosia purpurea both are nouns.

Word	Noun	Adjective	Verb	Adverb
bastard indigo	Yes	No	No	No
Tephrosia purpurea	Yes	No	No	No

As nouns, bastard indigo and Tephrosia purpurea are synonyms defined as:

bastard indigo (noun)	Tephrosia purpurea (noun)
East Indian shrub	East Indian shrub
an erect to spreading hairy shrub of the Pacific coast of the United States having racemes of red to indigo flowers
dense shrub of moist riverbanks and flood plains of the eastern United States having attractive fragrant foliage and dense racemes of dark purple flowers