P e t r a k , Die nordamerikanischen Arten der Gattung Cirsium. 409 
Synonyma: 
? Carduus discolor Hook. Flor. Bor. Amer. I, 302 (1833) 
p. p. nec Nutt., Gen. N. Amer. PI. II, p. 130 (1818). 
Cirsium canescens N.utt. in Trans. Amer. Phil. Soc. VII, 
p. 420 (1841). — Torr, et Gray, Flor. North Amer. II, 3, p. 461 
(1843). — Robinson et Fernald, Grays New Man. Bot. 7. ed. p. 857 
(1908). 
? Cirsium brevifolium Nutt. in Trans. Amer. Phil. Soc. VII, 
p. 421 (1841). — Torr, et Gray, Flor. North Amer. II, 3, p. 461 
(1843). 
? Cirsium undulatum ß. Torr, et Gray, Flor. North Amer. II, 
3, p. 456 (1843). 
Cirsium Hookerianum Hooker, Lond. Journ. Bot. VI, p. 253 
(1847) nec Nutt. in Trans. Amer. Phil. Soc. VII, p. 418 (1841). 
Cnicus undulatus var. canescens Gray in Proc. Amer. Acad. X, 
p. 42 (1874). — Coulter, Man. Bot. Rocky Mount. Reg., p. 214 
(1885). — Gray, Syn. hl. North Amer. II, p. 403 (1886). — Bessey 
in Contrib. Bot. Dept. Univ. Nebrask. New Ser. III, p. 41 (1892). 
Cnicus undulatus O. Kuntze Rev. Gen. plant., p. 329 (1891). 
Carduus undulatus canescens Porter in Mem. Torr. Bot. Club V, 
p. 345 (1893—95). 
Carduus Nebraskensis Britton in Britt. et Brown, Illustr. 
Flor. North U. S. III, p. 487, Fig. 4066 (1898). — Britton, Man. 
Fl. North. Stat. Canad., p. 1032 (1901). — Visher in Muhlen- 
bergia IX, p. 77 (1913). 
Cnicus canescens Pammel Thistl. Jow. in Proc. Jowa Acad. 
Sei. VIII, p. 20, tab. XIX et XXIX (1901). 
Carduus Flodmanni Rydberg, Cat. Fl. Mont, in Mem. N. Y. 
Bot. Gard. I, p. 451 (1900). — Britton, Mem. Fl. North Stat. 
Canad., p. 1031 (1901). 
Cirsium Flodmanni Petrak in Cirsiotheca universa Nr. 19 
(1911). — Arthur in Torreya XII, p. 34 (1912) sec. Ind. Americ. 
Cirsium, nebraskense Lunell in Amer. Midland Nat. II, P- 301 
(1912) sec. Ind. Americ. 
Cirsium nebraskense var. discissum Lunell in Amer. Midland 
Nat. II, p. 301 (1912) sec. Ind. Americ. 
? Carduus dakoticus A. Nelson ex Visher in Muhlenbergia IX, 
p. 77 (1913) nomen. 
Exsiccata: Petrak, Cirsiotheca universa Nr. 19, 49, 50. 
Distributio: In pratis siccis, arenosis, ruderatis, secus 
vias, in collibus sterilibus, apricis in eivitatibus boreali-centralibus 
Americae borealis nec non in regionibus meridionali-centralibus 
Canadensibus frequens. 
Vidi e locis sequentibus. 
Canada: Saskatchewan 1858 Coli. E. Bourgeau H. N. W. 
— Assiniboia Coli. ? H. H. 
N. D a k o t a: In pratis aridis circa urbem Leeds VII. 1909 
Coli. Dr. J. Lunell H. P. — In pratis siccis arenosis prope pagum 
„Mmot“ 9.— 12. IX. 1911 Coli. J. C. Blumer H. P. — Surrey, 
