rhododendron
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
Latin > English
rhododendron rhododendri N N :: rose-bay; oleander (Pliny)
Latin > French (Gaffiot 2016)
rhŏdŏdendrŏn, ī, n. (ῥοδόδενδρον), laurier rose, nérion : Plin. 26, 79.