ῥιζίον

τό
A. little root, Ar. Av. 654, Antiph. 45, Thphr. CP 2.18.2, HP 4.2.3, etc.; πορφύρα ῥιζίου vegetable purple (cf. ῥίζινος), POxy. 1051.13 (iii A.D.).
Liddell, Scott & Jones
A Greek-English Lexicon, 1940
An open-access project