ASTERACEAE: CYNAREAE 191 
Basal leaves, at least some of them, pinnatifid or crenate. 
Some of the basal leaves pinnatifid, persistently tomentose. 
4. S. plattensis. 
Basal leaves crenate, often purple, leaves glabrous or nearly 
so, stems often woolly, especially below. 5. S. balsamitae. 
Basal leaves linear or parted into linear segments, 
Basal leaves linear-cuneate, 4-6 mm. wide, the upper leaves usually 
laciniate or pinnatifid. 6. S. compactus. 
All the leaves linear or parted into linear segments. 
Leaves all linear, entire, 1-3 mm. wide. 7. S. spartioides. 
Leaves, at least some of them, parted into 3-9 linear segments. 
8. S. fremontil. 
1. Senecio integerrimus Nutt. 
Valentine. 
2. Senecio atriapiculatus Rydb. 
In moist soil in the eastern part of the state. Ainsworth; Lincoln; 
Ponca; Whitney. 
3. Senecio purshianus Nutt. 
In dry soil in the western part of the state. Belmont; Freeport; Hat 
Creek Basin; Pine Ridge; Sidney. 
4. Senecio plattensis Nutt. 
On prairies throughout the state. Callaway; Dawson; Ewing; Fair- 
bury; Lincoln; Naponee; Plainview. 
5. Senecio balsamitae Muhl. 
In prairies throughout the state. Emerson; Nebraska City. 
6. Senecio compactus (A. Gray.) Rydb. 
In dry prairies in the western part of the state. Callaway; Long Pine; 
Minden; Thedford; Valentine. 
7. Senecio spartioides Torr. & Gray. 
In dry prairies in the western part of the state. 
8. Senecio fremontii (T. & G.) Rydb. 
In dry soil in the western part of the state. Callaway; Crawford; 
Valentine. 
Tribe 10. CYNAREAE. 
Involucral bracts hooked at the tip, leaves not bristly. 1. Arctium. 
Involucral bracts not hooked at the tip. 
Leaves very spiny. 2. Carduus. 
Leaves not spiny. 3. Centaurea. 
1. Arctium. 1029. 
1. Arctium minus Schk. Common Burdock. 
Introduced in the eastern part of the state. Crete; Lincoln; Talmage. 
2. Carduus. 1030. 
Bracts of the involucre, at least the outer, strongly prickly pointed, 
heads all with perfect flowers over 25 mm. broad. 
All the involucral bracts prickly pointed. 1, C, lanceolatus. 
Inner bracts of the involucre merely acuminate or appendaged. 
Leaves glabrous, hispid or floccose above, tomentose beneath. 
