Page authors: Don Knoke, David Giblin
Marrubium vulgare
white horehound
Specimens
Photos

Distribution: Occurring on both sides of the Cascades crest in Washington Alaska to California, east across most of North America to the Atlantic Coast.

Habitat: Fields, roadsides, thickets, wastelots, and other disturbed areas.

Flowers: June-October

Origin: Introduced from Eurasia

Growth Duration: Perennial

Conservation Status: Not of concern

Description:
General:

White-wooly perennial from a stout taproot, the several stems nearly prostrate to sub-erect, 3-10 dm. tall.

Leaves:

Leaves opposite, all cauline, only slightly reduced upward, petiolate, the blades broadly elliptic to rotund-ovate, 2-5.5 cm. long and nearly as wide, with rounded teeth.

Flowers:

Flowers in dense whorls in the axils of normal leaves; calyx with stellate hairs, and a ring of long hairs in the throat; calyx tube 4-5 mm. long, with 10 narrow teeth nearly as long, their spiny tips recurved; corolla whitish, 2-lipped, the upper erect and narrowly 2-lobed, the lower spreading and 3-lobed, the central lobe broadly rounded; stamens 4, the lower pair longer, included in the corolla tube.

Fruits:

4 nutlets.

Accepted Name:
Marrubium vulgare L.
Publication: Sp. Pl. 2: 583. 1753.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Marrubium vulgare in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Marrubium vulgare checklist entry.

OregonFlora: Marrubium vulgare information.

E-Flora BC: Marrubium vulgare atlas page.

CalPhotos: Marrubium vulgare photos.

USDA Plants: Marrubium vulgare information.

25 photographs:
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