κολοκάσιον
From LSJ
ὃν οὐ τύπτει λόγος οὐδὲ ῥάβδος → if words don't get through, neither a beating will | if the carrot doesn't work, the stick will not work either | whom words do not strike, neither does the rod
English (LSJ)
[ᾱ], τό, Nic.Fr.82, Diph.Siph. ap. Ath.3.73a, Dsc.2.106; or κολοκασία, ἡ, Plin.HN21.87, v.l. in Dsc. l.c.:—A the root of κύαμος Αἰγύπτιος, Nelumbium speciosum, ll.cc., Verg.E.4.20, etc. 2 Κολοκασία, surname of Athena at Sicyon, Ath.3.72b.