846 CARDUACEAE 



heads subsessile, 2-5 together; disk- and ray-flowers each about 4. Dry plains: 

 Wyo. Colo. Submont. S-O. 



4. G. diversifolia Greene. Stems 1-2 dm. high, angled, scabrous; lower 

 leaves often oblanceolate, the rest linear, 2-4 cm. long, about 2 mm. wide, sca- 

 brous; inflorescence corymbiform; heads subsessile, clustered; bracts oblong, 

 with thick, obtuse or acutish tips; ray-flowers 5 or 6, disk-flowers 8-10. (?) G. 

 viridifolia Greene. Plains: Sask. N.M. Utah Alta. Submont. Jl-S. 



5. G. filifolia Greene. Stems 3-6 dm. high, puberulent; leaves 1-4 cm. long, 

 scabrous-puberulent; involucres obovoid- turbinate, 3-4 mm. long; outer bracts 

 ovate, acute, green-tipped, the inner obtuse, apiculate, scarcely at all green; 

 ligules about 3 mm. long; ray- and disk-flowers each 3 or 4. Dry plains: Ida. 

 N.M. Arizi Nev. Plain Submont. Au-O. 



6. G. divaricata (Nutt.) T. & G. Stem 2-4 dm. high, branched, glabrous 

 or nearly so; leaves 1-2 cm. long, about 0.5 mm. wide, glabrous, spreading; 

 involucre turbinate obconic, 4-5 mm. high; bracts lanceolate, acute, green-tipped; 

 ray-flowers 5 or 6; ligules 2 mm. long; disk-flowers 5-8. Plains: Wyo. Tex. 

 Utah. Plain Submont. Au-S. 



7. G. juncea Greene. Stems 1-2 dm. high; leaves 0.5 mm. wide, puberu- 

 lent, spreading, early deciduous; inflorescence corymbiform; involucre turbinate, 

 3 mm. long; bracts ovate, acute, green-tipped except the innermost; ray- and 

 disk-flowers each 4 or 5. Dry hills and plains: Okla. Colo. Ariz. Tex. 

 Plain Mont. Jl-Au. 



8. G. Sarothrae (Pursh) Britt. & Rusby. Stems 1-3 dm. high; leaves 

 puberulent; heads numerous in flat-topped cymes; involucres turbinate, 4 mm. 

 high; bracts oblong, acute, slightly green-tipped; ray-flowers 3-5; ligules 1.5-2 

 mm. long; disk-flowers 2-5. G. Euthamiae T. & G. G. myriacephala A. Nels. 

 Dry plains: Sask. Kans. Utah Alta. Plain Submont. Jl-S. 



9. G. longifolia Greene. Shrub 5-10 dm. high; young branches scabrous- 

 puberulent or nearly glabrous; leaves linear, 3-6 cm. long, 1-2 mm. wide, slightly 

 scabrous; inflorescence ample, flat-topped; heads subsessile, often 2 or 3 together; 

 involucre 4-6 mm. high; bracts with thick green obtuse or acutish tips; ray- and 

 disk-flowers eacli 4 or 5. Dry hills and 'plains: Colo. Utah N.M. Tex. 

 Plain Submont. Au. 



10. G. linearis Rydb. Shrubby and branched, 3-6 dm/ high; leaves linear, 

 about 3 cm. long, 1-2 mm. wide, puberulent and viscid, punctate; heads 5-6 

 mm. high; bracts scarious-margined; inflorescence corymbiform; heads subsessile, 

 2 or 3 together; ray- and disk-flowers each 3-4. Plains: Neb. Kans. N.M. 

 Colo. Plain Submont. Jl-S. 



11. G. glomerella Greene. Suffruticose, fastigiately branched, 4-6 dm. 

 high; branches of the season striate, glabrous; leaves linear-filiform, 2-4 cm. 

 long, about 1 mm. wide, scabrous-puberulent; inflorescence corymbiform; heads 

 sessile, 2-5 together; involucres oblong, 2 mm. high; bracts glutinous, oblong, 

 obtuse. Dry plains: Tex. Colo. Ariz. Plain Son. Au-S. 



8. AMPHIPAPPUS T. & G. 



Shrubs with glabrous foliage. Leaves alternate, small, entire. Heads numer- 

 ous, conglomerate in small clusters forming a corymb, radiate; involucres cam- 

 panulate, few-flowered; bracts leathery, imbricate in few series. Ray-flowers 1 

 or 2, short, pistillate and fertile. Disk-flowers hermaphrodite, but sterile, with 

 rudimentary glabrous ovaries. Achenes of the ray-flowers pubescent; pappus 

 of few and short bristles or scales, united at the base. Pappus of the disk- 

 flowers of about 20 flattish denticulate-hispid ulous tortuose bristles, some of 

 them branching or irregularly paleaceous-concreted at the base. 



1. A. Fremontii T. & G. A shrub 3-6 dm. high with rigid white branches; 

 leaves obovate or spatulate, about 1 cm. long; heads sessile and glomerate; invo- 

 lucres campanulate, 4 mm. high; bracts 7-9, thin, oval, without green tips; ray- 

 flowers 1 or 2, short; disk-flowers 3-6. Amphiachyris Fremontii A. Gray. Des- 

 ert regions: s Calif. Nev. s Utah. L. Son. 



