44 PROCEEDINGS OF THE AMERICAN ACADEMY 



C. Arizonicus. Albo-lanatus ; caule 2-4-pedaH ramoso folioso ; 

 foliis pectinato-pirmatifidis deiitatisve spinosis ; capitulis brevi-pedun- 

 culatis vel subsessilibus ; involucri squamis extimis ovato-oblongis, 

 scquentibusque lanceolatis iu acumen spina breviuscula superatum 

 angustatis ; corollas loI)is fauce duplo longioi'ibus ; antherarum appen- 

 dicibus fere obtusis ; styli appeudice stigmatiea supra nodum proinin- 

 ulum brevi ! Cirsiuin undidatum var. Gray, PL Wright. 2, p. 101. — 

 Arizona and S. Utah, C. Wright, Thurber, Palmer, Loew, Mrs. Thomp- 

 son, Parry. By the involucre, &c., related on the one hand to the 

 C. undulatus var. ochrocentruSy on the other to the following species. 

 Remarkable as being the oidy indigenous species of the United States 

 with a short stigmatic tip to the style, this being barely 4 to 6 times 

 longer than thick, and the node at its base manifest.* 



C. AxDERSONii. Minus lanatus ; caule bi-tripedali gracili parcius 

 foliato ; cajiitulis longius pedunculatis ; involucri squamis laxioribus 

 angustioribus plerisque e basi lanceolata sensim subidato-attenuatis 

 spinula brevissima cuspidatis, intimis tenuibus ; corollce lobis fouci 

 subaiquilong-is ; styli appendice filiformi longiuscula, nodo evanido. — 

 Sierra Nevada, California, and adjacent part of Nevada, Anderson, 

 Torrey, Bolander, &c. Head broader and rather larger than that of 

 the foregoing species. Tips of the anther-appendages deltoid and 

 acute, or in one specimen about as blunt as in G. Arizonicus. Addi- 

 tional specimens will show if this be a subsexual difference. 



§ 2. Involucrum laxius imbricatum ; squamis subsequalibus (extimisve 

 paullo brevioribus) superne subherbaceo-attenuatis vel in acumen 

 s£ei)ius spiuescentem patulum sensim productis. 



* MoUissime denseque albo-lanati, megacephali : involucri globosi 

 S(;[uama3 multiseriales rigida3, e basi coriacea appressa longe sj^ines- 



* The grefit-headed Mexican species, with outer reflexed or spreading scales 

 to the involucre sphiulose along tlie margins near the base, have abbreviated 

 tips to tlie style, and obtuse or merely acute anther-tips. 



Cnicus cernuus ( Cirsinm cernuum Lag. ; at least Linden's no. 1280 and Lieb- 

 mann's no. 689), which is probably also C. nimlis IIBK., has very obtuse antlier- 

 tips. Cirsiuin subcoriaceuvi Schult. Bip. (Seemann's no. 2040) seems to differ 

 only in its smaller head and less spreading involucral scales, and may be only 

 a variety. 



Cnicus heterolepis {Cirsium hcfcrolcpis Benth. PI. Hartw., or at least Coul- 

 ter's no. 4G7, and apparently Barclay's plant from Tepic, in Beechey's voyage) 

 is very like C. cernuus, but has acute anther-tips. Perhaps there is some dimor- 

 phism. 



