Flower profile

White horehound

Marrubium vulgare

White horehound (Marrubium vulgare) is a low shrub in the Lamiaceae family, introduced in the lower 48 states, blooming mostly April–June across the U.S.

Introduced in the lower 48

White horehound is a wildflower that USDA PLANTS lists as introduced in the lower 48 states. It's on our flower lists for 4 states, and across the U.S. it's most often seen in bloom in April–June.

46states where USDA records it

4Bloomipedia state lists include it

25,207U.S. sightings*

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

On our lists for: Arizona, California, Nevada, New Mexico

Quick look

Marrubium vulgare is a flowering plant in the mint family (Lamiaceae), native to Europe, northern Africa, and southwestern and central Asia. Specifically, it emerged in the region between the Mediterranean Sea and Central Asia and now inhabits all continents save Antarctica. It is also widely naturalized in many places, including most of North and South America.
From Wikipedia's article Marrubium vulgare, CC BY-SA 4.0.

It belongs to the Lamiaceae family. ^iNaturalist
USDA PLANTS describes it as an herb (forb) / a subshrub with a perennial life cycle. ^{USDA PLANTS}
USDA PLANTS lists it as introduced in the lower 48 states and records it in 46 states. ^{USDA PLANTS}
NatureServe lists it as not native to California, Arizona, New Mexico and Nevada. ^NatureServe
In California, most iNaturalist sightings of it in flower come in April–June. ^iNaturalist
iNaturalist has 18,563 research-grade sightings of it in California, ranking #26 among the 178 flowers on our California list. ^iNaturalist
iNaturalist has 1,184 research-grade sightings of it in Arizona, ranking #84 among the 132 flowers on our Arizona list. ^iNaturalist
iNaturalist has 957 research-grade sightings of it in New Mexico, ranking #55 among the 152 flowers on our New Mexico list. ^iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (555 records)

Bloom time in the 4 states whose Bloomipedia list includes it

State	Type	Peak bloom	Sightings*
California	Introduced	April–June	18,563
Arizona	Introduced	few records (15)	1,184
New Mexico	Introduced	few records (36)	957
Nevada	Introduced	few records (11)	609

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

State rare plant lists

Not listed Not on the official rare plant list in 4 of our 4 states.

See each state

California: Not listed Not on California state-listed endangered, threatened and rare plants (14 CCR § 670.2), per CDFW's CNDDB list (July 2026). NatureServe: SNA, not applicable (usually because it isn't native there) in California. ^{CNDDB listed plants (July 2026)}
Arizona: Not listed Not on Arizona Native Plant Law protected plants (Ariz. Admin. Code R3-3 Art. 11, App. A, eff. Feb. 2, 2025). NatureServe: SNA, not applicable (usually because it isn't native there) in Arizona. ^{AAC R3-3 App. A}
New Mexico: Not listed Not on New Mexico state endangered plant species (19.21.2.9 NMAC). NatureServe: SNA, not applicable (usually because it isn't native there) in New Mexico. ^{19.21.2.9 NMAC}
Nevada: Not listed Not on Nevada fully protected plants, critically endangered (NAC 527.010). NatureServe: SNA, not applicable (usually because it isn't native there) in Nevada. ^{NAC 527.010}

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 peopleEdible (per NC State Extension)

NC State Extension notes: “Teas and beer, cough remedy, and flavoring in hard candies and crafts are produced from the leaves.” ^{NC State Extension}

For petsNot well documented

It isn't on the ASPCA plant list, and NC State Extension doesn't flag it for pets.

🌿 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 white horehound in 46 states plus Washington, D.C.

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recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming; District of Columbia.

California counties with USDA records: Alameda, Alpine, Amador, Butte, Contra Costa, Fresno, Glenn, Humboldt, Kern, Lake, Lassen, Los Angeles, Madera, Marin, Mendocino, Merced, Modoc, Mono, Monterey, Napa, Nevada, Orange, Placer, Plumas, Riverside, Sacramento, San Benito, San Bernardino, San Diego, San Francisco, San Joaquin, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Shasta, Siskiyou, Solano, Sonoma, Stanislaus, Sutter, Tehama, Tulare, Ventura, Yolo.

Arizona counties with USDA records: Apache, Cochise, Coconino, Gila, Graham, Greenlee, La Paz, Maricopa, Mohave, Navajo, Pima, Pinal, Santa Cruz, Yavapai, Yuma.

New Mexico counties with USDA records: Bernalillo, Chaves, Colfax, Lincoln, McKinley, Mora, Rio Arriba, Roosevelt, San Juan, San Miguel, Sandoval, Santa Fe, Sierra, Socorro, Taos, Torrance, Union.

Names, range and relatives

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

County records: USDA PLANTS lists it in 675 counties across 42 states; the most are in Texas (60), Kansas (52), Missouri (46).

More from the Lamiaceae family (44 on Bloomipedia; most observed first): Common selfheal, Ground-ivy, Red deadnettle, American beautyberry, Henbit deadnettle, Wild bergamot, Lyreleaf sage, American germander.

More California flowers

Black sage

Salvia mellifera

Native

🌼 Blooms in CA: February–May

Chia

Salvia columbariae

Native

🌼 Blooms in CA: March–May

White sage

Salvia apiana

Native

🌼 Blooms in CA: April–June

Sources

USDA, NRCS. PLANTS Database, profile MAVU.
iNaturalist, Marrubium vulgare: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Marrubium vulgare (lead quoted under CC BY-SA 4.0).
California: California state-listed endangered, threatened and rare plants (14 CCR § 670.2), per CDFW's CNDDB list (July 2026).
California: California noxious weed species (3 CCR § 4500).
Arizona: Arizona Native Plant Law protected plants (Ariz. Admin. Code R3-3 Art. 11, App. A, eff. Feb. 2, 2025).
Arizona: Arizona prohibited noxious weeds (Ariz. Admin. Code R3-4-245).
New Mexico: New Mexico state endangered plant species (19.21.2.9 NMAC).
New Mexico: New Mexico Noxious Weed List (NM Department of Agriculture, updated June 2020).
Nevada: Nevada fully protected plants, critically endangered (NAC 527.010).
Nevada: Nevada noxious weeds (NAC 555.010).
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Marrubium vulgare (global and state ranks).
Edibility and toxicity: NC State Extension.
Photo: Sam Kieschnick via iNaturalist · CC BY 4.0 · resized.