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Marrubium vulgare - horehound

Scientific Family
Lamiaceae
Other common names
white horehound
Plant type
Forbs and Subshrubs
Origin
Introduced
Lifecycle
Perennial
Height
To 3 feet
Riparian
No
Rounded, bushy plant with white woolly stems and wrinkled leaves. Flower bracts have 10 hooked teeth and will readily stick to clothing and the fur of animals.
Taprooted perennial, stems trailing to ascending. Plant is densely woolly and pungent. Leaves wrinkled, opposite, thick and rounded with crinkled edges. Flowers are whitish, whorled in rounded clusters in leaf axils with spiny sepals. Fruit is a nutlet.

Habitat

Disturbed places, roadsides, fields and pastures.
Plant Community
Disturbed Areas
Low elevation
2000
High elevation
7500

Flower Characteristics

Tiny white flowers are up to 1/4 inch long in whorls around the stem in leaf axils.
Flower color
White
Flower shape
Irregular
Tubular
Yes
First bloom month
April
Last bloom month
September
Flower clusters
Rounded

Leaf and Stem Characteristics

Leaves are to 2 inches long. They have a wrinkly surface above, white woolly beneath. Leaves are found in pairs on the stem below each flower whorl.
Leaf type
Simple
Leaf color
Grayish-green
Leaf shape
Round or oval
Leaf margin
Toothed
Leaf attachment
Opposite
Leaves clasp
No
Leaf hairs
Leaves & stems
Spines
No

Fruit and Seed Characteristics

Black to dark brown nutlet.
Fruit type
Nutlet
Fruit color
Brown
One seed per nutlet, less than 1/16 inch long.