DIDYNAMIA G7MX0SPERMIA 349 



to 1 third of an inch wide, narrowed at base, minutely pubescent. Flowers in sub* 

 sessile clusters ; clusters in rather crowded one-sided terminal racemes, or spikes, 

 with a few distant ones btloto ; bracts lance-linear, acute, the inner ones short. 

 Calyx-teeth lanceolate, acuminate. Corolla bright blue, or sometimes purplish, 

 pubescent externally. 

 Hab. Gardens : frequent. Fi. July— August. Fr. September. 



Obs. Cultivated as a medicinal herb,— the infusion being a popular febrifuge. 

 It is the only species qfthe genus, as it is now constituted. 



279. COLLINSONIA. L. JSTutt. Gen. 26. 

 [In honor of Peter Collinson, of London ; a Patron of Botanical Science.] 



Calyx ovoid-campanulate, about 10-nerved, bilabiate; upper lip trun- 

 cate, flattish, 3-toothed ; lower lip bifid. Corolla exserted, campanu- 

 late, sub-bilabiate ; upper lip 4-lobed, lobes nearly equal ; lower lip long- 

 er, declined, toothed, or fimbriate ; throat dilated. Stamens mostly 2, 

 much exserted, diverging ; anthers 2-cellcd ; cells divaricate. 



J. C. canadensis, L. Leaves ovate, acuminate, coarsely serrate- 

 dentate, thin and smoothish, petiolate ; flowers diandrous, in loose ter- 

 minal paniculate racemes. Beck, Bot. p. 275. 



Also {fide Benth.), C. ovalis. Pursh, Am. I. p. 21. Ell. Sk. I. p. 35. 

 Lindl. Ency. p. 26. Eat. Man. p. 102. 



Canadian Collinsonia. Vulgo — Knot-root Horse Balm. 



Root perennial. Stem 2 to 3 feet high, somewhat branched, obtusely quadran- 

 gular, smooth, or sparingly pubescent, sometimes densely pubescent at summit. 

 Leaves 4 to 8 or 9 inches long, and 3 to 5 inches wide, thin and membranaceous, 

 nearly smooth, minutely resinous-punctate beneath, obtuse and rounded at base, or 

 often cuneate, serratures mucronate ; petioles 1 to 3 or 4 inches long,— the leaves 

 at the base of the panicle smaller, and sessile. Flowers in loose paniculate ra- 

 cemes ; branches and pedicels opposite, with minute lance-ovate acuminate bracts at 

 base ; pedicels 1 third to near half an inch long. Calyx smoothish ; teeth of the 

 1 )wer lip lanceolate, longer than the upper ones. Corolla greenish yellow ; lower 

 lip elongated, fringed ; tube exserted, dilated above,villose within. Stamens most- 

 ly 2, much longer than the corolla. Style rather shorter than the stamens, equally 

 bind and purple at apex. Akene, by abortion, mostly solitary (sometimes 2), glo- 

 bose, veined, smooth, of a livid color. 



Hab. Rich, rocky woodlands : frequent. Fl. July— August. Fr. September. 



Obs. This plant is mostly diandrous, by abortion, but I have occasionly obser. 

 ved a third slender stamen, in some of the flowers. The infusion of the root was 

 formerly a popular febrifuge. The odor of the flowers greatly resembles that of 

 Hops. Five additional species are enumerated in the U. States. 



280. CUNILA. L. J\Tutt. Gen. 22. 

 [A name borrowed from the ancient Roman Naturalists.] 



Calyx cylindric-tubular, 10-nerved, oqually 5-toothed ; throat densely 

 villosc. Corolla bilabiate ; upper lip erect, flattish, emarginate ; lower 

 lip spreading, 3-lobed, lobes nearly equal, entire, or the middle one a 

 little larger and emarginate. Stamens 2, erect, exserted, distant ; anth- 

 ers 2-colled ; cells parallel, or finally diverging at base. 



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