Native Range

Europe and Asia

Appearance

Houndstongue is a terrestrial forb that grows as a biennial or short-lived perennial from a taproot. Plants typically remain rosettes the first year and bolt the second year, growing 1–4 ft (30–120 cm) tall with ridged, hairy stems. Rosette leaves are hairy, elliptical, and up to 12 in (30 cm) long with long stalks. Stem leaves are smaller, stalkless, and alternate. Flowers are ¼–½ in (0.6–1.2 cm) across, have five reddish-purple petals, and are produced in fiddleneck clusters (= coiled at the tip). Each flower produces up to four nutlets covered in tiny barbed hooks.

Impact

Hoary cress is considered one of the worst weeds of agriculture in several parts of the world. It reduces pasture and crop production and is an alternate host for several important crop pests worldwide. It is mildly toxic to livestock, especially when large amounts are digested. Grazing animals exposed to hoary cress reportedly have tainted milk or meat up to a week after exposure. Hoary cress displaces native plant species, alters natural food webs, and may increase streamside soil erosion.

Reference

Andreas, J.E., R. De Clerck-Floate, and M. Maggio. 2022. Houndstongue (Cynoglossum officinale): History and Ecology in North America. In: R.L. Winston, Ed. Biological Control of Weeds in North America. North American Invasive Species Management Association, Milwaukee, WI. NAISMA-BCW-2022-4-HOUNDSTONGUE-P. https://bugwoodcloud.org/resource/files/27415.pdf

Selected Images

Maps

Invasive Listing Sources

• Alberta Weed Control Act
• California Invasive Plant Council
• Colorado Noxious Weeds
• Idaho Noxious Weeds
• Invasive Plant Species of West Virginia
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
• Montana Noxious Weeds
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• Nevada EDRR
• Nevada Noxious Weeds
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• North Dakota Noxious Weeds
• Oregon Noxious Weeds
• Pacific Northwest Exotic Pest Plant Council, 1998
• Utah Noxious Weeds - Contain
• Washington Noxious Weeds
• WeedUS - Database of Plants Invading Natural Areas in the United States
• West Virginia Invasive Species Strategic Plan and Volunteer Guidelines 2014
• West Virginia Native Plant Society, Flora West Virginia Project, and West Virginia Curatorial Database System, September 3, 1999
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40
• Wyoming Noxious Weeds

References