Lewis & Short

asphaltĭon, ii, n., = ἀσφάλτιον, a kind of clover with long leaves, and of the odor of asphaltum; among the Gr. μινύανθες, prob. the common bituminous clover: Psoralea bituminosa, Linn.; Plin. 21, 9, 30, § 54 (in Col. 6, 17, 2, written as Greek).