THISTLE FAMILY 955 



Leaves, except the earliest ones, pinnatifld with narrow divisions. 



3. G. pinnatifida. 

 Leaves entire or with broad divisions. 



Perennials with a thick root. 4. G. gracilis. 



Annuals or biennials; root not thick. 5. G. Mearnsii. 



Disk pale yellow; leaf-segments divaricate. 6. G. flava. 



Pappus-squamellae elliptic, muticous, or with a very short awn-tip; disk yellow. 

 Squamellae with a distinct midrib, usually minutely awn-tipped. 



7. G. Pringlei. 



Squamellae without midrib and awn-tip. 8. G. arizonica. 



Plant minutely and sparingly puberulent; caudex thick and woody; leaves coriaceous, 



conspicuously punctate. 



Plant distinctly caulescent; leaf-blades spatulate to linear. 9. G. spathulata. 



Plant acaulescent, scapose; basal leaf-blades broadly obovate. 10. G. Parryi. 



1. G. aristata Pursh. Stem 2-6 dm. high, simple, leafy, more or less hirsute 

 and puberulent; leaves oblanceolate in outline, the lower petioled, the upper 

 sessile, grayish-puberulent, entire, dentate, lobed, or pinnatifid; involucres 2-3 

 cm. broad; bracts lance-subulate, long-attenuate, surpassing the disk, hirsute- 

 villous; disk-corollas purple; ligules wholly yellow, or purplish at the base, 1.5-3 

 cm. long; pappus-squamellae lanceolate, long-aristate. G. bracteosa Standl. Hills 

 and plains : Sask. S.D. Colo. Ore. B.C. Submont. Je-S. 



2. G. pulchella Foug. Stem branched, leafy, 2-4 dm. high, puberulent; 

 lower leaves oblanceolate or spatulate in outline, petioled, puberulent, entire, 

 dentate or sinuately pinnatifid, the upper leaves sessile, lanceolate, acute or 

 acuminate; involucres 15-20 mm. broad; bracts lanceolate, acuminate, hirsute; 

 disk-flowers purple; ligules 10-18 mm. long, purple below with yellow tips, or 

 sometimes wholly purple; Squamellae lanceolate, long-aristate. Plains: La. 

 Mo. Neb. Colo. Ariz.; n Mex. Son. Plain. Ap-Au. 



3. G. pinnatifida Torr. Perennial, often branched at the base; stem 1-3 

 dm. high, leafy towards the base; leaves short-pubescent, pinnatifid, with linear 

 or lanceolate divisions, or some of the earlier merely lobed; peduncles 1-2 dm. 

 long; involucres 15-20 mm. broad; bracts lance-subulate, attenuate, hirsute, 

 often purplish; ligules yellow, 10-15 mm. long; squamellae lanceolate, long- 

 aristate. Dry plains: Tex. Colo. Utah Ariz. ;n Mex. Son. Submont. My- 

 Au. 



4. G. gracilis A. Nels. Stems usually several, 3-5 dm. high, straw-colored, 

 finely puberulent; leaves short-pubescent, oblanceolate in outline, 4-8 cm. long, 

 entire, lobed, rarely sinuate-pinnatifid with obtuse lobes; involucres 1.5-2 cm. 

 wide; bracts narrowly lanceolate, attenuate, pubescent; ligules yellow, about 

 15 mm. long; squamellae lanceolate, abruptly acuminate. Dry valleys and can- 

 yons: Utah. Son. My. 



5. G. Mearnsii Rydb. Stem 1-3 dm. high, leafy only towards the base, 

 finely pubescent; leaves oblanceolate or spatulate, petioled, 5-10 cm. long, 

 puberulent, entire or round-lobed; peduncles 1-2 dm. high; involucres about 2 

 cm. broad; bracts lanceolate, acute, grayish-pubescent; ligules yellow, 10-15 mm. 

 long; squamellae lanceolate, each gradually attenuate into a slender awn equal- 

 ling the corolla. Arid places: Ariz. Utah. Son. 



6. G. flava Rydb. Perennial, somewhat woody at the base; stem leafy, 

 sparingly hirsutulous, about 3 dm. high; leaves obovate in outline, 3-5 cm. long, 

 pinnately parted with divergent oblong or lanceolate, often few-toothed divisions, 

 hirsutulous and conspicuously punctate; involucral bracts lanceolate, long- 

 acuminate, hirsutulous; ligules pale yellow, about 8 mm. long; squamellae 5-6 

 mm. long, lanceolate, the midrib produced into an awn between the lobes of the 

 2-cleft apex. Canons: Utah. Son. Jl. 



7. G. Pringlei Rydb. A subscapose annual; leaves clustered at the base, 

 4-6 cm. long, usually pinnately lobed or sometimes merely toothed, with ovate 

 lobes or teeth, villous; scape 1-2 dm. high, short-pubescent; involucral bracts 

 8 mm. long, villous; ligules yellow, 10-15 mm. long; disk yellow, 15-18 mm. 

 broad ; squamellae 8-10, obovate, rounded or slightly retuse at the apex. Mesas : 

 Ariz. Utah. Son. 



