942 CARDUACEAE 



cent, 5-8 cm. long; head solitary, 1.5-2 cm. high; bracts linear-lanceolate, viscid- 

 pubescent and more or less villous; rays light yellow, less than 1 cm. long. Among 

 rocks: Mont. — Wyo. — Ida. Subal-p. — Alp. Jl-Au, 



^ 



95. CEPHALOBEMBIX Rydb. 



Slender gland alar-hirsute annuals. Leaves impressed-punctate, pinnately 

 dissected into linear-filiform divisions, the lower opposite, the upper alternate. 

 Heads discoid, corymbose. Involucres turbinate or obconic; bracts 5-8, obovate, 

 scarious and more or less colored around the margins. Flowers hermaphrodite 

 and fertile; corollas light yellow, glandular on the tube. Style-branches with short 

 acute appendages. Achenes elongate-obpyramidal, 4-angled, hispidulous on 

 the angles below. Pappus of 8 scarious squamellae. 



1. C. neomexicana (A. Gray) Rydb. Stem branched, 1-2 dm. high, spar- 

 ingly strigose or glabrate; leaves pinnately divided into 3-5 linear divisions, 

 which are entire or the lowest 2-3-cleft; involucres about 6 mm. high and 8 mm. 

 broad; bracts about 10, striate. Bahia neomexicana A. Gray. Sandy soil: N.M. 

 — Colo. — Ariz. ; Mex. Son, — SnbmonL Au-0. 



96. HYMENOPAPPUS L'Her. 



More or less tomentose-floccose perennials or biennials, with mostly 1-2-pin- 

 nately divided leaves. Heads corymbose or rarely soKtary, discoid. Involucre 

 hemispheric, or nearly so; bracts 6-12, in 1-2 series, subequal, appressed, more 

 or less colored and scarious-margined. Receptacle naked. Disk-flowers all 

 perfect and fertile; corollas yellow. Styles with short conic appendages. Achenes 

 mostly obpyramidal, 4-5-angled, the faces 1-3-nerved. Pappus of 10-20 hya- 

 line obtuse scales without costa, or none. 



Throat of the corolla campanulate, 1-2 nun. long, not over twice as long as the lobes. 

 Pappus over 1 mm. long, equalUng the coroUa-tube or nearly so. 

 Stem 3—6 dm. high, leafy throughout; heads numeroias. 



Plant sparingly and loosely floccose; leaves glabrate in age. I. H. tenuifolius. 

 Plant densely tomentose; leaves permanently tomentose. 2, H. tomentosus. 

 Stem less than 3 dm. high. 



Stem-leaves much reduced; stem white-torn entose or nearly so; heads few. 



3. H, scaposus. 



Stem-leaves not much reduced; stem sparingly grajish-tomentose. 



5. H. cinereus. 



Pappus 1 mm. or less long, much shorter than the corolla-tube; stem-leaves and heads 



few. 

 Pappus not hidden by the hairs of the achenes. 



Stem permanently densely white-tom entose; achenes silky. 4. II. arenosus. 

 Stem sparingly grayish-tom.entose, glabrate in age; achenes loosely villous. 



5. H. cinereus. 



Pappus hidden by the haiis of the achenes, or sometimes none. 



Leaflets glabrate in age, at least above; ultimate segment 5—30 mm. long. 



6. H. filif alius. 



Leaves permanently densely white-tomentose; ultimate segments short, 1-5 

 mm. long. 7. H. luieus. 



Throat of the coroUa cylindro-campanulate, 1.5-4 mm. long. 3-4 times as long as the 



lobes. 

 Pappus ecLualling the corolla-tube; plant dwarf. 



Heads less than 1 cm. high and broad; corolla-tube 1.5-2 mm. long; stem not 

 woolly at the base. 8. H. parvulus. 



Heads over 1 cm. high and 1.5 cm. broad; coroUa-tube 3-4 nun. long; stem woolly 



at the base. 

 Bracts more or less rose- or purple-tinged. 9. H. lugens. 



Bracts yellow-tinged. 3. if. scaposus. 



Pappus shorter than the corolla-tube; throat 3-4 mm. long; plant 2-4 dm. high. 

 Stemleafy at least half its height, decidedly woolly at the base. 10. if. eriopodus. 

 Stem leafy only at the base, not conspicuously woolly. 11. if. macroglottis. 



1. H. tenuifolius Pursh. Biennial or short-lived perennial, slightly tomen- 

 tose, in age often glabrate, 3-6 dm. high, branched and leafy; leaves except the 

 uppermost 1-3 pinnately divided into Unear divisions, 5-30 mm. long; heads 

 numerous, 8-12 mm. broad; corollas dirty white or cream-colored; achenes 

 densely pubescent. Plains and dry prairies: N.D. — Wyo.-j-N.M. — Tex. — Ark, 

 Plain, Je-S. 



