COLLINSONIA — HOUSK-BALM. 211 



IFabilnf. — ^IfiHaachuHotts to Illinois mid HoutUwanl. 



J'artfi L'.stv/. — Tho licrlj — nut olliciul. 



Constituenln. — Mountuiu-mint has a tiwto intcnuoiliato between thui. ui 

 pcnuyroyal ami Bpearuiint, duo to it« volatile oil, its only important (;on- 

 htituent. Virginia thynio has much lesH aroma, and luoro bittt.'rness ; it 

 contaiurt volatile oil, tannin, a bitter prinfii)le, etc. 



l'rci>ar(th'oiis. — Used in infusion. 



Medical l'ri>in;rlicK and I'si's. — Tiic abovo-described species of pycnan- 

 theuuini, together with several others oi similar properties, have been used 

 medicinally to a limited extent, for the same puqioses as other labiate 

 plants are employed. As they are less agreeable than many others of the 

 order in coninion use, and are certainly no mure etlicieut, tlu;y do not de- 

 mand serious attention. 



lll':i)I':(JMA.— Mock PicNNYUovAf.. 



f edeoma pulegioides Persoon. — American Penny royal 



V 'svripliixn. — (Jalyx KJ-ncrved, gibbous at the base, 2-lippcd, the 

 throat bearded; the upper lip ;{-toothed ; the lower 2-clcft and spined. 

 Corolla 2-lipped ; the ui)i)er li^) erect, flat, notched at the a[)ex ; the louver 

 31obed, spreading. Stamens 2 iertilo and 2 rudimentary. 



A low annual. .Stem erect, (5 inches high, branching. Leaves oblong- 

 ovate, obscurely serrate, petiolaie. Flowers bluish, in few llowered, axillary 

 whorls, appearing throughout the summer. 



Ilahilal. — In (b'y fields and open woods ; everywhere (iommon. 



Parts lT»ed. — The leaves and tops. — Ciiiled Slate.s Pharmacupoma. 



GouHtitueMx. — Its chief and only important constituent is an aromatic 

 volatile oil. 



PreparaLiun!^.—0\i}\\\\\ hedeoma? — oil of hedeonia (o/7 i>f penmiroifd). — 

 Cniled Stales Pliarmaeopfvia. li'iK often administered in infusion. 



Medical Properties and f^ses. — Pennyroyal is an aromatic^ stimulant, 

 long used in flatulence, and to stinmlate menstruation. In the latter case 

 it is not to be considered as exerting, in any sen.se, a specific action, but 

 simply as stimulating the secretions through its general stimulant proper- 

 ties, and not through any special action upon the organs engaged in the 

 function of menstruation. 



COLLINSONIA.— Hokse-Bai.m. 



Collinsonia Canadensis Linm'. — Horse-Balm, Stone-Root. 



Description. — Calyx 2-lipped ; the upper lip IMootlied, the lower 2-cleft. 

 Corolla greenish-yellow, somewhat 2-lipped, the throat expanded ; the 

 upper lip nearly equally idobed, the lower much larger, the margin 

 fringed. Stamens 2, rarely 4, much exserted. 



