What is a white crystalline substance which is obtained indirectly from the root of an umbelliferous plant (Imperatoria Oreoselinum), and yields resorcin on decomposition called?

oreoselin — A white crystalline substance which is obtained indirectly from the root of an umbelliferous plant (Imperatoria Oreoselinum), and yields resorcin on decomposition. (Webster's 1913.)

Sources