510 
The plant may be a form of the next. Rochford, altitude 1,650 m., July 11; Hot 
Springs, altitude 1,050 m., August 8 (No. 825). 
Senecio integerrimus Nutt. Gen. ii, 165 (1818). 
This resembles a specimen collected by Mr, Nicollet, which according to Torrey 
and Gray ! is 8. integerrimus Nutt. The other specimens in the National Herbarium 
seem to belong to some other species. The type specimens of Nuttall I have not 
seen. The bracts and the base of the involuere are somewhat fleshy. Prairie, near 
Squaw Creek, Hermosa, altitude 1,050 m., June 23 (No. 826). 
Senecio balsamitz Muhl.; Willd. Sp. Pl. iii, 1998 (1804). 
Leaves very thin and wholly glabrous, bright green, the lower obovate, serrate. 
Lead City, altitude 1,600 m., July 6; Rochford, altitude 1,600 m., July 11; Custer, 
altitude 1,700 m., July 16 (No. 827). 
Senecio plattensis Nutt. Trans. Amer. Phil. Soc. ser. 2, vii, 418 (1841). 
Hot Springs, altitude 1,100 m., June 18 (No, 828). 
Senecio canus Hook. Fl. Bor. Aimer. 1, 333 (1834). 
This is a very variable species. Three forms were collected, one of them the 
typical. This is3to5dm. high, densely woolly; root leaves entire, broadly oblance- 
olate, oblong, or spatulate; 7 to 10 cm. long, 1 to 1.5 em. wide, Battle Mountain, 
near Hot Springs, altitude 1,200 m., June 18; Lead City, altitude 1,700 m., July 4 
(No. 829), The second form is somewhat like the last but greener with deciduous 
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 alow form with narrow leaves, the lower narrowly spatulate 
or oblanceolate, 3 to 7 em. long and about 4 mm. wide, white woolly, with more or 
less revolute margins. Dry table-land: Hot Springs, altitude 1,100 m., June 18 
(No. 831). 
Carduus undulatus Nutt. Gen. ii, 180 (1818); Cnicus undulatus Gray, Proc. Amer. 
Acad. x, 42 (1874). 
Custer, altitude 1,650 m., August 12 (No, 882). 
Carduus undulatus ochrocentrus, nom. nov.; Cnicus undulatus ochrocentrus Gray, 
Proc. Amer. Acad. x, 43 (1874); Cirsium ochrocentrum Gray, Pl. Pend]. 110 (1849) ; Cnicus 
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. The 
northern form is, I think, only a variety, and differs only in the prickles of the invo- 
luere, which are much longer and stouter. Intermediate forms are sometimes seen. 
Custer, altitude 1,650 m., August 1 (No. 853), 
Carduus drummondii (Gray); Cnicus drummondii Gray, Proc. Amer. Acad. x, 
40 (1874). 
Some of the specimens are very near to the variety acaulescens Gray. Meadows: 
Custer, altitude 1,650 m., July 16 (No. 854), 
Centaurea cyanus L. Sp. Pl. ii, 911 (1753). 
Only one specimen collected: Roadside, not far from Hot Springs, altitude 1,100 m.,, 
August 2 (No. 835). 
Hieracium canadense Mx. I'l. ii, 86 (1803). 
The specimens referred to this species have much thinner, narrower, and less den- 
tate leaves than the common form, Custer, altitude 1,650 m., July 12 (No, 836). 
Hieracium umbellatum L. Sp. Pl. ii, 804 (1753). 
The specimens of this have fewer heads than usual. Wet meadow: Rapid City, 
altitude 1,000 m., June 25 (No, 837). , 
LPL, ii, 439. 
