GENUS 36. MINT FAMILY. 
12. Mentha gentilis L. Creeping or Downy 
Whorled Mint. Spearmint. Fig. 3691. 
Mentha gentilis L. Sp. Pl. 377. 1753. 
Mentha sativa L. Sp. Pl. Ed. 2, 805. 1763. 
Perennial by suckers; stem rather stout, ascend- 
ing or erect, branched, glabrous or puberulent 
with short reflexed hairs, 1°-2° high. Leaves 
ovate or oval, short-petioled, sparingly pubescent 
with scattered hairs on both surfaces, often blotch- 
ed, pinnately veined, acute at both ends, sharply 
serrate, the larger 13’-2’ long, the upper some- 
times much smaller than the lower; whorls of 
flowers all axillary; pedicels glabrous; calyx cam- 
panulate, glabrous below, its teeth subulate, ciliate, 
one-half as long as the tube; corolla glabrous. 
In waste places and along streams, Nova Scotia to 
northern New York, Iowa, North Carolina and Ten- 
nessee. Naturalized from Europe. Aug.—Oct. 
37- COLLINSONIA L. Sp. Pl. 28. 
1733. ; 
Tall perennial aromatic herbs, with large membranous petioled leaves, and terminal 
loosely panicled racemes of small, yellowish, mostly opposite flowers. Calyx campanulate, 
short, Io-nerved, 2-lipped, declined in fruit, usually pubescent in the throat; upper lip 3-toothed; 
lower 2-cleft. Corolla much longer than the calyx, obliquely campanulate, 5-lobed, 4 of the 
lobes nearly equal, the 5th pendent or declined, fimbriate or lacerate, much larger, appearing 
like a lower lip. Anther-bearing stamens 2, not declined, much exserted, coiled before 
antithesis; bases of the filaments connected by a woolly ring; anthers 2-celled, or the sacs 
at length partially confluent. Ovary deeply 4-parted. Nutlets smooth, globose. [Named for 
Peter Collinson, 1693-1768, an English botanist, and correspondent of Linnaeus.] 
Three species, natives of eastern North America, the following typical. 
I. Collinsonia canadénsis L. Horse- or Ox-balm. Citronella. Rich-weed. 
Fig. 3692. 
Collinsonia canadensis L. Sp. Pl. 28. 1753. 
Stem stout, erect or ascending, branch- 
ed, 2°-5° high, glabrous, or glandular- 
pubescent above. Leaves ovate or ovate- 
oblong, acuminate at the apex, narrowed, 
obtuse or sometimes cordate at the base, 
the lower slender-petioled, 6-10’ long, the 
upper nearly sessile, much smaller, all 
coarsely dentate; racemes numerous, in 
terminal panicles sometimes 1° long; pedi- 
cels ascending, 3’-6” long in fruit, subu- 
late-bracteolate at the base; flowers lemon- 
scented; calyx-teeth subulate, those of the 
lower lip much longer than the upper; 
corolla light yellow, 5’-7” long: anther- 
bearing stamens 2. the upper pair rudi- 
mentary; fruiting calyx ribbed, 3’—4” long. 
In moist woods, Quebec and Ontario to 
Wisconsin, south to Florida, Alabama and 
Arkansas. Root large, thick, woody. Knob- 
or horse-weed. Knob-grass or -root. Collin- 
son’s-flower. Richleaf. Stone-root. July—Oct. 
38. PERILLA <Ard.; L. Gen. Pl. Ed. 6, Add. 578 1764. 
Annual herbs, with petioled purple or discolored leaves, and small flowers in loose 
bracted racemes. Calyx campanulate. 10-nerved, 5-cleft, nearly regular in flower. enlarging, 
declined and becoming 2-lipped in fruit, the upper lip 3-toothed. the lower 2-cleft, the throat 
not bearded. Corolla-tube not longer than the calyx, the throat obliquely campanulate, the 
limb 5-cleft, the lower lobe slightly the larger. Stamens 4. nearly equal, or the posterior 
