LAMIACEiE. 513 



M. vdlgare, Linn. — Branches white-woolly. Leaves round ish-ovate, wrinkled, crenate, 

 softly villous. Whorls many-flowered. Calyx woolly, with ten bristly, recurved teeth. 



Linn., Sp. PL 816; Torrey, Comp. 235; Lindley, Flor. Med. 494; 

 Stephenson and Churchill, iii. 135. 



Common Names. — Horehound ; White Horehound. 



Foreign Names. — Marrube blanc, Fr.; Marrobio bianco, i£.; Witte mal- 

 rove, Ger. 



The Horehound is a native of most parts of Europe; is also found in 

 Asia, and has become naturalized in some places in the United States. It 

 grows in waste grounds and among rubbish, especially in warm, dry situations, 

 flowering in July and August. The whole plant is officinal. It has a strong 

 and peculiar aromatic odour, and a bitter, somewhat pungent taste, which is very 

 permanent. According to an analysis by Mr. M'Maken (Am. Jour. Pharm. 

 xi. 1), it contains Resin, Tannic acid, Volatile oil, a peculiar crystallizable 

 Bitter principle, &c. This bitter principle is insoluble in water, but soluble in 

 ether, and more so in hot than in cold alcohol, is perfectly neutral, and melts 

 like resin when heated. 



Medical Properties. — Horehound is tonic, somewhat stimulant and diuretic, 

 and in large doses is gently laxative. It was at one time in much repute in 

 asthma, jaundice, and visceral and uterine obstructions. It is seldom em- 

 ployed at the present day in regular practice, but is a favourite domestic 

 remedy in diseases of the pulmonary organs, and some cases of obstinate 

 catarrhs have been much benefited by the expressed juice taken in milk. It 

 is administered in powder, in doses of about a drachm, but more frequently in 

 infusion made with an ounce of the dried herb to a pint of boiling water, and 

 given in doses of a wineglassful several times a day. It also enters into the 

 composition of several cough syrups and candies. 



Collinsonia. — Linn. 



Calyx bilabiate ; upper lip three-toothed, lower bifid. Corolla much longer than the 

 calyx, somewhat infundibulifbrm, unequally 5-lobed ; the lower lobe longest, fimbriated. 

 Stamens 4, two of which are often sterile. Seeds 4, often 2 — 3 abortive. 



A small North American genus of herbaceous plants, with large opposite 

 leaves, and flowers in terminal panicles of a yellowish-violet colour. It was 

 named by Linnaeus, in honour of Peter Collinson, so advantageously known 

 for his zeal and liberality in the promotion of science and learning in the then 

 British Colonies. This genus is sometimes diandrous and sometimes tetran- 

 drous, but in all the species the fertile stamens are exserted. 



C. canadensis, Linn. — Leaves broad, cordate, ovate, smooth. Teeth of the calyx short, 

 subulate. Panicle compound, terminal. 



Linn., Sp. PL, 40; Torrey, Compend.^ 24; Rafinesque, Med. Fl. i. 

 iii. t. 23. 



Common Names. — Horse-weed ; Rich-weed ; Knot-weed ; Heal-all, &c. 



It is found in many parts of the United States, between the Atlantic and 

 the mountains, but is more rare in the Southern States ; very frequent in rich 

 valleys in New York and Pennsylvania. It flowers from July to September, 

 and is a curious and rather handsome plant. The whole plant has a peculiar 

 balsamic smell, which is milder and pleasanter in the flowers than in the root, 

 this having somewhat a rank odour. It affords on distillation an essential oil, 

 which possesses the same odour. The taste of both is pungent and warm. 

 No analysis has been made of it. 



33 



