orchal
Webster's Dictionary (GCIDE)
Archil \Ar"chil\ (?; 277), n. [OF. orchel, orcheil, It. orcella, oricello, or OSp. orchillo. Cf. Orchil.]
1.A violet dye obtained from several species of lichen (Roccella tinctoria, etc.), which grow on maritime rocks in the Canary and Cape Verd Islands, etc. --Tomlinson. [1913 Webster]
2.The plant from which the dye is obtained. [Written also orchal and orchil.] [1913 Webster]