IN'DIGO-PLANT, noun A plant of the genus Indigofera, from which is prepared indigo. It is a native of Asia, Africa and America, and called by the native Americans, anil. The calyx is patent; the carina of the corol is furnished with a subulate, patulous spur on each side; the legume or pod is linear. Several species are cultivated for making indigo, of which the most important are the tinctoria, or common indigoplant, the anil, a larger species, and the disperma, which furnishes the Guatimala indigo.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI