Flower profile

Hoary alyssum

Berteroa incana

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 May–October.

38states

6of our state lists

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
From Wikipedia's article Berteroa incana, CC BY-SA 4.0.

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 May–September. ^iNaturalist
In Michigan, most iNaturalist sightings of it in flower come in June–November. ^iNaturalist
iNaturalist has 3,580 research-grade sightings of it in Minnesota, ranking #18 among the 110 flowers on our Minnesota list. ^iNaturalist
iNaturalist has 3,129 research-grade sightings of it in Michigan, ranking #40 among the 111 flowers on our Michigan list. ^iNaturalist
iNaturalist has 2,256 research-grade sightings of it in Wisconsin, ranking #59 among the 109 flowers on our Wisconsin list. ^iNaturalist

State flower gift ideas

This one is a regulated invasive plant, so here are state flower gifts instead.

🌱 Sample spot. Handmade gift picks from independent shops will appear here once our shop partnership is approved. These cards are placeholders, not real products.

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State flower print
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Birth-flower necklace
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Wildflower seed favors
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Botanical tea towel
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Pressed-flower frame
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Flower-garden mug
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When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (1,454 records)

Bloom time in each of our 6 states

State	Type	Peak bloom	Sightings*
Minnesota	Introduced	May–September	3,580
Michigan	Introduced	June–November	3,129
Wisconsin	Introduced	June–October	2,256
Colorado	Introduced	June–October	1,754
Montana	Introduced	June–October	668
North Dakota	Introduced	June–September	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.

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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.

More Minnesota flowers

Garlic mustard

Alliaria petiolata

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🌼 Blooms in MN: April–May

Dame's rocket

Hesperis matronalis

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🌼 Blooms in MN: May–June

Cut-leaved toothwort

Cardamine concatenata

Native

🌼 Blooms: March–May

Sources

USDA, NRCS. PLANTS Database, profile BEIN2.
iNaturalist, Berteroa incana: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Berteroa incana (lead quoted under CC BY-SA 4.0).
Minnesota: Minnesota endangered, threatened and special concern plants (Minn. R. 6134.0300).
Minnesota: Minnesota Noxious Weed List (Minn. Stat. § 18.79; Minnesota Department of Agriculture, updated January 2026).
Michigan: Michigan endangered and threatened plants (Mich. Admin. Code R 299.1028, eff. March 20, 2023).
Michigan: Michigan prohibited and restricted species (NREPA Part 413 and the 2026 Invasive Species Order), as listed by Michigan's Invasive Species Program.
Wisconsin: Wisconsin endangered and threatened species list (Wis. Admin. Code NR 27.03).
Wisconsin: Wisconsin invasive species rule (Wis. Admin. Code NR 40.04 prohibited, NR 40.05 restricted).
Colorado: Colorado noxious weed lists A, B and C (8 CCR 1206-2, eff. May 15, 2025).
Montana: Montana noxious weed list (Admin. R. Mont. 4.5.206–4.5.210).
North Dakota: North Dakota state noxious weeds (N.D. Admin. Code 7-06-01-02), as listed by the ND Department of Agriculture.
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Berteroa incana (global and state ranks).
Edibility and toxicity: NC State Extension; ASPCA.
Photo: Brighton Lee via iNaturalist · CC0 · resized.