The genus comprises annual and perennialherbaceous plants or (rarely) small shrubs, growing to 10-100 cm tall, with oblong-oval leaves and yellow or white flowers (pink to purple in a few species).
The genera Lobularia and Aurinia are closely related to Alyssum and were formerly included in it. The widely cultivated species popularly known as "Sweet Alyssum" is Lobularia maritima. The common rockery plant is Aurinia saxatilis.
