ASTERACEAE: ASTEREAE 177 
21. Aster exiguus (Fernald.) Rydb. 
Aster multiflorus exiguus Fernald. 
Callaway; Loup City; Red Cloud; Wood River. 
22. Aster polycephalus Rydb. 
Nebraska according to Rydberg’s Flora of Colorado. 
23. Aster commutatus Torr & Gray. 
On prairies in the western part of the state. Hat Creek Basin; Wood 
River. 
12. Leucelene. 965. 
1. Leucelene ericoides (Torr.) Greene. 
In dry soil in the western part of the state. Perkins County. 
13. Brachyactis. 966. 
1. Brachyactis angustus (Lindl.) Britton. Rayless Aster. 
In wet saline soil. Lincoln. 
14. Machaeranthera. 966. 
Leaves pinnatifid. 1. M. tanacetifolia. 
Leaves incised dentate. 2. M. sessiliflora. 
1. Machaeranthera tanacetifolia (H. B. K.) Nees. ‘ 
In dry soil in the western part of the state. Crawford. 
2. Machaeranthera sessiliflora (Nutt.) Greene. 
In dry soil in the western part of the state. Chadron; Crawford; Hat 
Creek Basin; Kennedy; Merriman; Valentine. 
15. Erigeron. 966. 
Roots perennial, thick and woody. 
Lower leaves lanceolate, oblong or spatulate. 
Rays 100-150, violet or purple, stem leaves not linear. 
Upper leaves much smaller than the lower, linear-lanceolate. 
1. E. asper. 
Upper leaves not much smaller than the lower, ovate-lanceolate. 
2. E. subtrinervis. 
Rays 40-60, mostly white, stem leaves linear. 3. E. caespitosus. 
Leaves all linear, rays 40-80. 
Hispid or hirsute with spreading bristly hairs. 
Rays white. 4. E. pumila. 
Rays violet or blue, rarely white. 5. E. concinnus. 
Pubescence appressed, silvery. 6. E. canus. 
Roots fiberous not thick or woody, annual or biennial. 
Rays 100-150. 
Pappus simple, rays pink, plant stoliniferous. 
7. E. philadelphicus. 
Pappus double, the outer very short, plant not stoliniferous 
8. E. divergens. 
Rays less numerous. 
- Low, 1-3 dm. high, leaves linear spatulate. 9. E. bellidiastrum. 
Taller, basal leaves spatulate or oblong, often serrate. 
Pubescence appressed or sometimes strigose. 10. E. ramosus. 
Pubescent minute sometimes almost cinerous, plant slender, 
heads small. 10a. E. ramosus var. beyrichii. 
