Hoary alyssum

Berteroa incana (L.) DC.

Life cycle

Annual, biennial or short-lived perennial. 

hoary alyssum plant
Hoary alyssum flowering plant.

Leaves

Seedling leaves initially develop from a basal rosette. Basal leaves are hairy, oblong and up to 3 inches long with smooth to slightly wavy margins and long stalks. Stem leaves are similar but smaller and alternate and gradually become stalkless. Leaves are covered with gray, star-shaped hairs that result in a grayish green appearance.

hoary alyssum seedling hoary alyssum hairs
Hoary alyssum seedling (left). Gray, star-shaped hairs (right). 

Stems

Erect, stiff, up to 4 feet tall. Stems bolt from a basal rosette to flower. Up to 10 stems may form per taproot with many branches near the top. Stems are covered with gray, star-shaped hairs that result in a grayish green appearance. 

Flowers and fruit

Numerous white flowers with four petals so deeply divided that they resemble eight petals, are found in elongated clusters. Fruit are hairy, oval and slightly flattened, grayish green seed pods with a short beak on the end. Seed pods are usually held close to the stems and yield oblong, rough and narrowly winged, grayish to reddish brown seeds.

hoary alyssum flowers hoary alyssum seed pod
Hoary alyssum flowers (left) and seed pods (right).

Reproduction

Seeds and root crowns

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