THISTLE FAMILY 955 



Leaves, except the earliest ones, pinnatifld ynth 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, Afearnsii, 



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



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

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



7. G. PringJei, 

 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. scauose; basal leaf-blades broadly obovate. 10. G. Parryi. 



V 



1. G. aristata Pursh. Stem 2-6 dm. bigh^ 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; ligxdes wholly yellow, or purplish at the base, 1.5-3 

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

 and plains: Sask.— S.D.— Colo.— Ore.—B.C. SubmonL 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. So?i.— Plain. Ap-Au. 



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

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



anceolate divisions, or some of the earlier merely lobed; pedimcles 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.—S ubmonL My- 

 Au. 



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

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

 ^T.+iro loKoH TQrplv simmtft-ninnatifid with obtuse lobes: involucres 1.5-2 cm. 



dm 



wide; bracts narrowly Ian- 

 15 mm. long; squamellae k 

 yons: Utah. Son, My. 



5. G. Mearnsii Rydb. 



acuminate. Dry valleys and can- 



Stem 1-3 dm. high, leafy only towards the base, 

 uiit^iv uuuc^v^xxu, .^^r^^ .^lanceolate or spatulate, petioled, 5-10 cm. long, 

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

 cm broad; bracts lanceolate, acute, grayish-pubescent; Hgules yellow, 10-15 mna. 

 long; squamellae lanceolate, each gradually attenuate mto 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 em, long, 

 pmnately 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; squameUae 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, 

 4r-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, 



