20 LAWSON: EEVISION OF TUE 



Clematis verticillaris. De Candolle, Syst. Nat. Eeg. Veg., Vol. I., p. 166. (1818.) Pro- 

 dromus, I., p. 10. Hooker, Fl. Bor.-Am., I., p. 2. Torrey & Gray, Fl. N. Am., I., p. 10. 

 Maclagan, Trans. Bot. Soc. Edin., III., p. 13. Loud. Jour. Bot., VI., p. 66. Torrey, Fl. N. 

 Y., I., p. *7. "Wood, Botany, p. 201. Gray, Manual, ed. 5, p. 35. Provancher, Fl. Can., p. 

 4. Lawson, Eanuuc. Can., p. 20. Bot. Wilkes, p. 212. "Watson, King's Eep., V., p. 4. 

 Porter, Hayd. Rep., 18n, p. 41*7. Coulter, same, 1812, p. YSS. Watson, Bibl. Index, I., 

 p. 11. Macoun, Cat. (1883), No. 1. .1. F. James, Revis. Clematis, pp. 3, 11, and 19. Brewer 

 & Watson, Botauy of California, ed. 2, Vol. I., p. 3. 



Atragene Americana. Sims, Bot. Mag., t. 88*7. Alton f., Hortus Kewensis, ed. 2, III., 

 p. 342, (1811). Pursh, FL, p. 384. Spreng., Sysi, II., p. 644. Watson, Deud. Brit., p. "74, 

 (1825). Don, Mill. Diet., I., p. 10. Spach, Hist. Veg., VI., p. 2*70. Dietr. Syn., III., p. 340. 

 Loudon, Arboret., I., p. 248, t. 2*7. Hort. Brit., p. 228. Gray, Gen. Illus., p. 14, t. 1. 

 Manual, 2 ed., p. 3. Revue Horticole, 1854, t. *7, and 1855, t. 1*7. Curtis, Bot. N. Carolina, 

 p. 120. Chapman, Fl. South. U. S., p. 3. 



C. Americana. Poiret, Supp., V., p. 622. (1810-16.) 

 A. Columbiana. Nuttall, Jour. Ac. Phil., VII., p. *7. 

 C. Columbiana. Torr. & Gr., Fl. N. Am., I., p. 11. (Watson.) 



The species was originally described in the Botanical Magazine as Atragene Americana, 

 De Candolle, in " Regni Vegetabilis Systema Naturale," did not adopt the genus Atragene, 

 but merged it in Clematis, as Poiret had previously done. Poiret called it C. Americana. 

 But there being already a Clematis Americana, described in Miller's Dictionary, from Ec]ua- 

 torial America, and adopted by De Candolle, the latter botanist had to find a new specific 

 name for the Northern American plant, now transferred to Clematis, and accordingly called 

 it C. verticillaris, in allusion to the apparent verticils of leaves subtending the flowers. In 

 the Hortus Britannicus, its English name is given as the Whorled American Atragene. 

 So far as observed, the limits of the range of this species are as follows : 



Pacific Coast Region. — South limit (Northern California) 40° N. Lat. 



North limit (British Columbia) 50" " 



(Extent of range, N. to S.=10°.) 



Rocky Mountain Region. — South limit 40' " 



North limit (Mount Selwyn) 56' " 



(Extent of range N. to S.=16°.) 

 Elevation limits : Teton, 48' N.=11,000 ft. 

 Utah, 40° N.= 9,000 " 



Central Continental Region. — South limit (Wisconsin) 46° " 



North limit (Hudson Bay) 54° " 



(Extent of range, N. to S.=9°.) 



Atlantic Coast Region. — South limit (Carolina Mountains) 3*7° " 



North limit (Maine, Vermont, Montreal) 45° " 



(Extent of range, N. to S.=8°.) 



Extreme South Limit (Carolina Mountains) 37° " 



Extreme North Limit (Rocky Mountains) 56° " 



In woods in the central districts, as far north as lat. 54°, ascending the elevated valleys 

 on the eastern declivity of the Rocky Mountains in that latitude. — Richardson, T. Drum- 

 mond. At Cape Mendocino, on the N.W. coast, in lat. 40°, plentiful (North California). — 



