510 



Tlu" ])lant may Ix' :> form of llio jicxt. K'oflironl. altitiidc l,(!ri() m.. .Inly 11; Hot 

 Springs, altitudr 1,(I5() iii., August S (No. 825). 



Seiiecio iutegerrimus Nntt. (Jen. ii, 165 (1818). 



This rt'S(]iiT)lts a siiociiuen collected l)y Mr. Nicollet, Avliicli according to 'I'orrey 

 and Gray ' is A. //(/q/crr(Hi/(N Nntt. The other specimens in the National llerhariuni 

 eeem to helong to some other species. The ty))e specimens of Nnttall I havi^ not 

 seen. The bracts and the base of the involucre are somewhat lieshy. I'rairie, near 

 Squaw Creek, llennosa. altitude 1,0.50 m., .Tune 23 (No. 82(5). 



Senecio balsamitae Mnhl. ; Willd. Sp. PI. iii, 1908 (1804). 



J^eavos very thin and Avholly glabrous, bright green, the lower obovate, seriate. 

 Lead City, altitude l,fiOO m., July (">; Rochford, altitude 1,60(^ ni., July 11 ; Custer, 

 altitude 1.700 im., .Inly 1(> (No. 827). 



Senecio plattensis Nutt. Trans. Amer. Phil. Soc. ser. 2, vii, 4i:i (1H41). 



Hot Springs, altitude 1,100 m., June 18 (No. 828). 



Senecio canus Hook. IT. Bor. Amor, i, 333 (1834). 



This is a very variable species. Three forms were collected, one of them the 

 typical. This is 3 to 5 dm. high, densely wocdly ; root leaves entire, broadly oblanee- 

 olate, oblong, or spatulate;,? to 10 cm. long, 1 to 1.5 cm. wide. Battle Mountain, 

 near Hot Springs, altitude 1,200 m., June 18; Lead City, altitude 1,700 m., July 4 

 (No. 8211). The second form is .somewhat like the last but greener with decidncms 

 wool and thin leaves. It approaches .somewhat the preceding species, especially as 

 to the involucre, which is nearly glabrous. Lead City, altitude 1,600 m., July 6 

 (No. 830). The third is a low form with narrow leaves, the lower narrowly spatulate 

 or oblanceolate, 3 to 7 cm. long and about 4 nun. wide, white woolly, with more or 

 less revolute margins. Dry table-land: Hot Springs, altitude 1,100 m., June 13 

 (No. 831). 



Carduus undulatus Nutt. Gen. ii, 130 (1818); ('7ii(iiH uuthdaliis (Jray, Proc. Anwr. 

 Acad. X, 42 (1874). 



Custer, altitude 1,650 m.. August 12 (No. 8.32). 



Carduus undulatus ochrocentrus, nom. nov. ; Ciiicua undiihifns ochroceniriifi Gray, 

 Proc. Amer. Acad, x, 43 (1874) ; Cirsium ochroccntnim Gray, PI. Feinll. 110 (1849) ; Cuicus 

 ochrocentrus Gray, Proc. Amer. Acad, xix, 57 (1883). 



This is the northern form referred to Carduus ochrocentrus. The southern, that 

 is, the original form, differs in being stouter and more white with broader bracts. 

 Whether the latter is distinct from C. undulatus I am not prepared to decide. Tlie 

 northern form is, I think, only a variety, and dilVers only in the i»rickles of the invo- 

 lucre, which are nnich longer and stouter. Intermediate forms are sometimes seen. 



Custer, altituib- 1,650 ni., August 1 (No. 833). 



Carduus drummondii (Gray); Cn'icux druuuiitiud'i'i (iray, Proc. Anu-r. Acail. x, 

 40(1874). 



Some of the specimens are very near to the variety acaulrscciis (Jray. Mi-adous: 

 Custer, altitude 1.6.50 m., July 16 (No. 834). 



Centaurea cyauus L. Si». IM. ii, !>11 (1753). 



Only one specimen collected : Koadside, not far from Hot S))rings, altitude 1,100 m., 

 August 2 (No. 8^5). 



Hieracium canadeuse Mx. Fl. ii, 86 (1803). 



The specimens referred to this species have nincli thinner, narrower, and less den- 

 tate leaves than the common form. Custer, altitude l,(r>() m.. .Inly 12 (No. 836). 



Hieracium umbellatum L. Sp. PI. ii. SOI (17.53). 



The specimens of this have fewer In-ads th.in usual. Wet meadow : l.'ai)id City, 

 altitude 1,000 in., Juno 25 (No. 837). 



' I'l. ii, 13!t. 



