31. 
souri, Ohio, and Michigan. In southern California this plant has 
proved a most troublesome weed, occurring almost everywhere and 
growing in such dense masses as to crowd out all other vegetation. 
Jt has spread rapidly over thousands of acres, taking complete pos- 
session of the land and destroying pastures. 
Description.—The entire plant has a whitish, woolly appearance, 
caused by the dense covering of hairs. It is a perennial plant, and as 
will be seen from the characteristic lip-shaped flowers, is a member of 
the mint family (Menthacez). The whole plant has a rather pleasant, 
balsamic odor. . 
Hoarhound is a bushy, branching herb, with fibrous roots sending 
up numerous woolly stems about 1 to 3 feet high, rounded below and 
Fig, 21.—Hoarhound (Marrubium vuigare L.). 
four-angled above. The leaves are opposite each other, 1 to 2 inches 
long, oval or nearly round, wrinkled, somewhat blunt at the apex, 
narrowed or somewhat heart shaped at the base, with rounded teeth, 
somewhat hairy and wrinkled on the upper surface, and prominently 
veined and very hoary on the lower surface. The flowersare whitish, 
two-lipped, the upper lip two-lobed, the lower three-lobed, and are 
borne in dense, woolly clusters in the axils of the leaves. (Fig. 22.) 
The plant flowers from June to September, and the characteristic 
hooked calyx teeth of the mature flower clusters cling to the wool of 
sheep like a bur, resulting in the scattering of the seeds. 
Parts used.—The leaves and tops are used in medicine. These 
should be gathered just before the herb is in flower, rejecting the 
coarse stalks, and should be dried in the shade in the usual manner. — 
188 
