What is a European perennial succulent herb (Cotyledon umbilicus), having round, peltate leaves with a central depression; -- also called pennywort, and kidneywort called?

navelwort — A European perennial succulent herb (Cotyledon umbilicus), having round, peltate leaves with a central depression; -- also called pennywort, and kidneywort. (Webster's 1913.)

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