33 



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. 

 It 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 (Menthacea?). 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 



9-&. 



Fig. -il.— Hoarhound (Marrvbium mdgare 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, 

 nan-owed 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 flowers are 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. 



16503— No. 188—04 3 



