| Noun | 1. | phytotoxin - any substance produced by plants that is similar in its properties to extracellular bacterial toxin nicotine - an alkaloid poison that occurs in tobacco; used in medicine and as an insecticide strychnine - an alkaloid plant toxin extracted chiefly from nux vomica; formerly used as a stimulant brucine - a bitter alkaloid poison resembling strychnine and extracted from nux vomica hemlock - poisonous drug derived from an Eurasian plant of the genus Conium; "Socrates refused to flee and died by drinking hemlock" toxin - a poisonous substance produced during the metabolism and growth of certain microorganisms and some higher plant and animal species mycotoxin - a toxin produced by a fungus curare, tubocurarine - a toxic alkaloid found in certain tropical South American trees that is a powerful relaxant for striated muscles; "curare acts by blocking cholinergic transmission at the myoneural junction" |