Hemlock

(1.) Heb. rosh (Hos. 10:4; rendered "gall" in Deut. 29:18;
32:32; Ps. 69:21; Jer. 9:15; 23:15; "poison," Job 20:16;
"venom," Deut. 32:33). "Rosh is the name of some poisonous plant
which grows quickly and luxuriantly; of a bitter taste, and
therefore coupled with wormwood (Deut. 29:18; Lam. 3:19). Hence
it would seem to be not the hemlock cicuta, nor the colocynth or
wild gourd, nor lolium darnel, but the poppy so called from its
heads" (Gesenius, Lex.).

(2.) Heb. la'anah, generally rendered "wormwood" (q.v.), Deut.
29:18, Text 17; Prov. 5:4; Jer. 9:15; 23:15. Once it is rendered
"hemlock" (Amos 6:12; R.V., "wormwood"). This Hebrew word is
from a root meaning "to curse," hence the accursed.