934 CARDUACEAE 



Paleae of the receptacle soft and scarious. 



Disk 2-3 cm. in diameter; leaves ovate to lanceolate, thin, not strongly reticulate. 



1. H. quinqucncrvis. 

 Disk less than 2 cm. wide; leaves oblanceolate to linear, strongly reticulate. 



Disk about 1.5 cm. wide, yellow; bracts linear-lanceolate, subequal, in about 2 



series. 2. //. Parnji. 



Disk about 1 cm. broad, piu"ple; bracts unequal, in 3-4 series. 



Ligules 5-6 mm. long. 3. H. microcephala. 



Ligules more than 1 cm. long. 4. //. scabra. 



Paleae of the receptacle flrm-chartaceous. 



Stem more or less liirsute, rarely glabrous; leaves thin, not strongly reticulate. 



5. //. Douglasii. 

 Stem more or less scabrous-puberulent; leaves rather firm and reticulate. 



6. H. uniflora. 



1. H. quinquenervis (Hook.) A. Gray. Stem 5-15 dm. high, glabrous or 

 sparingly hirsute; leaves mostly opposite; blades ovate-lanceolate or elliptic- 

 lanceolate, acuminate, 1-2.5 dm. long, usually with two pairs of the lateral veins 

 prominent, sparingly hirsute; heads long-peduncled, nodding; involucres about 

 2 cm. high and 4-5 cm. broad; bracts lanceolate, acuminate, hirsute-ciliate ; 

 ligules 15-20, pale yellow, 2.5-3 cm. long. Mountains, along streams: S.D. — 

 N.M.— Utah — Ida. — Mont. Submont. — Mont. Jl-Au. 



2. H. Parryi A. Gray. Stem slender, about 3 dm. high, hirsute; the lower 

 leaves opposite, petioled, the upper subsessile, mostly alternate ; blades oblanceo- 

 late or elliptic, 2-10 cm. long, rigid, triple-veined; heads rather short-peduncled; 

 involucres 10-12 mm. high, 15-20 mm. broad; bracts linear-lanceolate, attenu- 

 ate, hirsute-ciliate; ligules about 15 mm. lon^. Mountains: Colo. — N.M. — 

 Ariz. Mo7U. Jl-Au. 



3. H. microcephala A. Gray. Stem 2-4 dm. high, paniculately branched, 

 scabrous-hispidulous; leaves ridged, all but the lower alternate; basal leaves 

 petioled, spatulate, scabrous; stem-leaves linear or nearly so, sessile; involucres 

 about 1 cm. high and broad; bracts lanceolate, obtuse, hirsute; ligules 5-6 mm. 

 long. Dry plains and canons: sw Colo. — Utah — N.M. Son. 



4. H. scabra Payson. Stems several, 6-8 dm. high, cymosely branched; 

 leaves dark green, coriaceous, linear-lanceolate to linear, the lower 1.5-2.5 dm. 

 long, petioled; bracts lanceolate, acute; paleae truncate, ciliate at the apex; 

 hgules 8-10, orange, more than 1 cm. long; pappus of two awns and several lacer- 

 ate squamellae. Ravines: w Colo. Au. 



5. H. Douglasii T. & G. Stem 4-10 dm. high, more or less hirsute or gla- 

 brous below; leaves mostly opposite, the lower oblanceolate, petioled, triple- 

 veined, hirsute, 8-12 cm. long, the upper lanceolate, sessile; involucres about 

 15 mm. high and 3 cm. broad; bracts linear-lanceolate, attenuate, hirsute-ciliate; 

 ligules 2.5-3 cm. long. Hillsides and pine-land: Mont. — w Wyo. — Ore. — B.C. 

 Submont. Je-Jl. 



6. H. uniflora (Nutt.) T. & G. Stem 3-6 dm. high, puberulent; leaves 

 mostly opposite, petioled or the uppermost sessile, oblong-lanceolate, 5-12 cm. 

 long, scabrous, obtuse; involucres 12-15 mm. high, 2.5-4 mm. broad; bracts 

 lanceolate, acute, hirsute-ciliate on the margins; ligules 2-3 cm. long. H. multi- 

 caulis D. C. Eat. Hills and mountains: Mont. — N.M. — Nev. — Ida. Submont. 

 — Mont. 



77. XIMENESIA Cav. 



Annual caulescent herbs, ours canescent. Leaves alternate or sometimes op- 

 posite, toothed or lobed. Heads sohtary or few, radiate, peduncled. Invo- 

 lucres rather flat; bracts narrow, spreading, foliaceous, nearly equal. Ray- 

 flowers pistillate, fertile; hgules yellow. Disk-flowers numerous, hermaphrodite, 

 fertile. Anthers somewhat sagittate at the base. Style-branches with slender 

 pubescent appendages. Achenes flat, winged. Pappus of short awns, without 

 intermediate scales. 



1. X. exauriculata (Robins. & Greenm.) Rydb. Annual, with a taproot; 

 stem 3-6 dm. high, white-tomentose ; leaf -blades ovate or rhombic-lanceolate, 

 saUently dentate, minutely strigose but green above, densely white-strigose 



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