Bloomipedia
Hoary alyssum (Berteroa incana)
Photo: Brighton Lee via iNaturalist · CC0 · resized

Flower profile

Hoary alyssum

Berteroa incana

Hoary alyssum (Berteroa incana) is a flowering plant in the Brassicaceae family, introduced in the lower 48 states, blooming mostly June–September across the U.S.

Introduced in the lower 48

Hoary alyssum is a wildflower that USDA PLANTS lists as introduced in the lower 48 states. It's on our flower lists for 6 states, and across the U.S. it's most often seen in bloom in June–September.

38states where USDA records it
6Bloomipedia state lists include it
14,774U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Colorado, Michigan, Minnesota, Montana, North Dakota, Wisconsin

🚫
Regulated invasive plant in Montana. It's on that state' official invasive plant list (Montana: Priority 2B noxious weed). Please don't plant or share it there. ARM 4.5.206–210

Quick look

Berteroa incana is a species of flowering plant in the mustard family, Brassicaceae. Its common names include hoary alyssum, false hoary madwort, hoary berteroa, and hoary alison. It is a biennial herb native to Eurasia and it has been introduced to western Europe and North America. It is listed as an invasive noxious weed in some areas of United States and Canada

  • It belongs to the Brassicaceae family. iNaturalist
  • USDA PLANTS describes it as an herb (forb) with a annual, biennial, perennial life cycle. USDA PLANTS
  • USDA PLANTS lists it as introduced in the lower 48 states and records it in 38 states. USDA PLANTS
  • NatureServe lists it as not native to Minnesota, Michigan, Wisconsin, Colorado, Montana and North Dakota. NatureServe
  • In Minnesota, most iNaturalist sightings of it in flower come in June–August. iNaturalist
  • In Michigan, most iNaturalist sightings of it in flower come in June–August. iNaturalist
  • iNaturalist has 3,580 research-grade sightings of it in Minnesota, ranking #18 among the 152 flowers on our Minnesota list. iNaturalist
  • iNaturalist has 3,129 research-grade sightings of it in Michigan, ranking #40 among the 172 flowers on our Michigan list. iNaturalist
  • iNaturalist has 2,256 research-grade sightings of it in Wisconsin, ranking #59 among the 161 flowers on our Wisconsin list. iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (1,454 records)
Bloom time in the 6 states whose Bloomipedia list includes it
StateTypePeak bloomSightings*
MinnesotaIntroducedJune–August3,580
MichiganIntroducedJune–August3,129
WisconsinIntroducedJune–September2,256
ColoradoIntroducedJune–September1,754
MontanaIntroducedfew records (26)668
North DakotaIntroducedfew records (23)85

Conservation status

Federal (U.S. ESA)
Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
NatureServe global
GNR Not yet ranked worldwide. NatureServe
Minnesota
Not listed Not on Minnesota endangered, threatened and special concern plants (Minn. R. 6134.0300). NatureServe: SNA, not applicable (usually because it isn't native there) in Minnesota. Minn. R. 6134.0300
Michigan
Not listed Not on Michigan endangered and threatened plants (Mich. Admin. Code R 299.1028, eff. March 20, 2023). NatureServe: SNA, not applicable (usually because it isn't native there) in Michigan. R 299.1028
Wisconsin
Not listed Not on Wisconsin endangered and threatened species list (Wis. Admin. Code NR 27.03). NatureServe: SNA, not applicable (usually because it isn't native there) in Wisconsin. NR 27.03
Colorado
No list Colorado has no state law listing endangered or threatened plants, so we show NatureServe's Colorado ranks instead. NatureServe: SNA, not applicable (usually because it isn't native there) in Colorado.
Montana
No list Montana has no state law listing endangered or threatened plants, so we show NatureServe's Montana ranks instead. NatureServe: SNA, not applicable (usually because it isn't native there) in Montana.
North Dakota
No list North Dakota has no state law listing endangered or threatened plants, so we show NatureServe's North Dakota ranks instead. NatureServe: SNA, not applicable (usually because it isn't native there) in North Dakota.
Rare elsewhere
No other U.S. state ranks it S1, S2, SH or SX.

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Can you eat it?

For peopleNot well documented

None of the sources we checked (NC State Extension (no edibility or poison notes on its page), USDA PLANTS) say whether it's edible or poisonous for people. NC State Extension

For petsToxic to horses (not dogs or cats)

ASPCA's entry “Hoary Alyssum” (Berteroa incana) lists it as toxic to horses, but non-toxic to dogs and cats. Signs include: Fever, swollen limbs, laminitis, bloody diarrhea, abortion, death Credit: Image courtesy of Robert Garner, PBase Gallery… ASPCA

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records hoary alyssum in 38 states.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alaska, Arkansas, Colorado, Connecticut, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Dakota, Tennessee, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming.

Minnesota counties with USDA records: Aitkin, Anoka, Becker, Benton, Big Stone, Blue Earth, Carlton, Cass, Chisago, Clay, Clearwater, Crow Wing, Dakota, Douglas, Fillmore, Goodhue, Hennepin, Houston, Hubbard, Isanti, Itasca, Kanabec, Kittson, Koochiching, Lac qui Parle, Lake, Lake of the Woods, Lyon, Martin, Morrison, Mower, Norman, Otter Tail, Pennington, Pine, Polk, Ramsey, Scott, Sherburne, St. Louis, Stearns, Todd, Traverse, Wabasha, Washington, Winona, Wright.

Michigan counties with USDA records: Alcona, Alger, Allegan, Alpena, Antrim, Arenac, Barry, Bay, Benzie, Berrien, Branch, Calhoun, Cass, Charlevoix, Cheboygan, Chippewa, Clare, Clinton, Crawford, Delta, Dickinson, Eaton, Emmet, Genesee, Gladwin, Grand Traverse, Gratiot, Hillsdale, Houghton, Ingham, Ionia, Iosco, Isabella, Jackson, Kalamazoo, Kalkaska, Kent, Keweenaw, Lake, Lapeer, Leelanau, Lenawee, Livingston, Macomb, Manistee, Marquette, Mason, Mecosta, Midland, Missaukee, Monroe, Montcalm, Montmorency, Muskegon, Newaygo, Oakland, Oceana, Ogemaw, Oscoda, Otsego, Ottawa, Presque Isle, Roscommon, Sanilac, Schoolcraft, Shiawassee, St. Joseph, Van Buren, Washtenaw, Wayne.

Wisconsin counties with USDA records: Adams, Ashland, Barron, Bayfield, Brown, Buffalo, Burnett, Calumet, Chippewa, Clark, Columbia, Crawford, Dane, Dodge, Door, Douglas, Fond du Lac, Forest, Grant, Green, Green Lake, Iowa, Jackson, Jefferson, Kenosha, Kewaunee, La Crosse, Lafayette, Langlade, Lincoln, Manitowoc, Marathon, Marinette, Marquette, Menominee, Milwaukee, Monroe, Oconto, Oneida, Outagamie, Ozaukee, Pierce, Polk, Portage, Price, Racine, Richland, Rock, Rusk, Sauk, Sawyer, Shawano, Sheboygan, St. Croix, Taylor, Trempealeau, Vernon, Vilas, Walworth, Washburn, Washington, Waukesha, Waupaca, Waushara, Winnebago, Wood.

Names, range and relatives

Native status by region (USDA PLANTS): Alaska: Introduced; Canada: Introduced; Lower 48 states: Introduced.

Other scientific names (synonyms in USDA PLANTS): Alyssum incanum.

County records: USDA PLANTS lists it in 483 counties across 36 states; the most are in Michigan (70), Wisconsin (66), Minnesota (47).

More from the Brassicaceae family (24 on Bloomipedia; most observed first): Garlic mustard, Dame's rocket, Cut-leaved toothwort, Wild radish, Milkmaids, Annual honesty, Western wallflower, European searocket.

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Common milkweed (Asclepias syriaca)

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Sources