Hemlock
the common ground or dwarf hemlock, a bitter, poisonous plant. The Hebrew rosh is rendered "hemlock" in two passages, Ho 10:4; Am 6:12 but elsewhere "gall." [GALL] (It is possible that the plant is rather the poppy than an hemlock. --Cook.)
Bibliography Information Smith, William, Dr "Definition for 'Hemlock' Smiths Bible Dictionary". bible-history.com - Smiths; 1901.