What is a white, crystalline, poisonous substance, regarded as a glucoside, extracted from the lily of the valley (Convallaria Majalis). Its taste is first bitter, then sweet called?

convallamarin — A white, crystalline, poisonous substance, regarded as a glucoside, extracted from the lily of the valley (Convallaria Majalis). Its taste is first bitter, then sweet. (Webster's 1913.)

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