Weed Seed: Berteroa incana (Hoary alyssum)

Family

Brassicaceae

Common Name

Hoary alyssum

Regulation

Primary Noxious, Class 2 in the Canadian Weed Seeds Order, 2016 under the Seeds Act.

Distribution

Canadian: Occurs in AB, BC, MB, NB, NS, NT, ON, QC, SK (Brouillet et al. 2016^Footnote 1).

Worldwide: Native to east central Europe and Asia and introduced to North America and other parts of Europe (USDA-ARS 2016^Footnote 2).

Duration of life cycle

Annual or short-lived perennial

Seed or fruit type

Seed

Identification features

Size

• Seed diameter: 1.3 - 2.0 mm

Shape

• Round or oval seed with a narrow wing (> 0.1 mm) around the margin, flattened

Surface Texture

• Seed is roughened with reticulations

Colour

• Seed is dark reddish-brown

Other Features

• Hilum is a notch along the narrow edge filled with white tissue.
• Seed pod is elliptic to ovoid, 5.0 - 8.0 mm long with a persistent style (1.0 - 4.0 mm), and covered in stellate hairs.

Habitat and Crop Association

Cultivated fields, old fields, pastures, hayfields, meadows, grasslands, woodlands, streambanks, roadsides, railways, turf and disturbed areas (FNA 1993+^Footnote 3, Darbyshire 2003^Footnote 4, Warwick and Francis 2006^Footnote 5).

General Information

Hoary alyssum thrives on dry, calcareous, disturbed soils of low fertility (Parkinson et al. 2010^Footnote 6). It grows in a variety of habitats and is able to compete with native plants (Warwick and Francis 2006^Footnote 5).

Seed is dispersed by valves in the seedpod, and falls near the parent plant. Some wind and water dispersal may occur as the seed is light in weight and has a winged margin (Mangold and Jacobs 2010^Footnote 7, Parkinson et al. 2010^Footnote 6).

Similar species

Small alyssum (Alyssum alyssoides)

• Small alyssum has a similar oval shape with a marginal wing, strongly flattened, similar hilum notch with tissue, and similar reticulate surface texture as hoary alyssum.
• Small alyssum seeds are oval, a light reddish-brown, and the wing is yellow. Hoary alyssum seeds are usually round, with the seed and wing a dark reddish-brown.

Photos

Similar species