alyssum (n.)

type of European flowering plant, 1550s, from Latin alysson, from Greek alysson, which is perhaps the neuter of adjective alyssos "curing madness," from a- "not, without" (see a- (3)) + lyssa "madness, martial rage, fury," an abstract word probably literally "wolf-ness" and related to lykos "wolf" (see wolf (n.)); but some see a connection with "light" words, in reference to the glittering eyes of the mad.