Noun | 1. | genus Alyssum - a genus of the family Cruciferae dilleniid dicot genus - genus of more or less advanced dicotyledonous trees and shrubs and herbs Brassicaceae, Cruciferae, family Brassicaceae, family Cruciferae, mustard family - a large family of plants with four-petaled flowers; includes mustards, cabbages, broccoli, turnips, cresses, and their many relatives |