hoary alyssum
Berteroa incana (L.) DC

Overview

Appearance

Berteroa incana is an annual, biennial, or perennial in the mustard family growing 1-3 ft. (0.3-0.9 m) tall.

Foliage

Stems are gray-green and hairy with many branches near the top. Alternate leaves are gray-green, hairy, alternate, oblong, narrow, 0.5-3 in. (1.3-7.6 cm) long, with smooth edges.

Flowers

White flowers with 4 deeply divided petals are produced in long raceme.

Fruit

Seed pods are hairy, swollen, and oblong with short beaks on the end. Oblong seeds are rough, dull gray-brown. It reproduces and spreads by seeds.

Ecological Threat

Spreads rapidly due to the high number of seeds per plant. The plant emerges early in spring and continues to flower and produce seed until frost. It can cause toxicity to horses.

Resources

• Weed of the Week - USDA Forest Service

Selected Images

Maps

Invasive Listing Sources

• Alberta Weed Control Act
• California Invasive Plant Council
• California Noxious Weeds
• Idaho Noxious Weeds
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• Michigan Noxious Weeds
• Montana Noxious Weeds
• Oregon Noxious Weeds
• Pacific Northwest Exotic Pest Plant Council, 1998
• Washington Noxious Weeds
• WeedUS - Database of Plants Invading Natural Areas in the United States

References