| hoary alyssum n. An annual European herb (Berteroa incana) of the mustard family, having silvery foliage, oblong fruits, and deeply notched white flowers. It is naturalized in eastern North America. Also called alyssum. |
| hoary alyssum | |
noun | |
| tall European annual with downy grey-green foliage and dense heads of small white flowers followed by hairy pods; naturalized in North America; sometimes a troublesome weed [syn: hoary alison] |