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. SubalpAlp. Jl-Au. 



95. CEPHALOBEMBIX Rydb. 



Slender glandular-hirsute annuals. Leaves impressed-punctate, pinnately 

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

 Heads discoid, corymbose. Involucres turbinate or pbconic; 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. Submont. Au-O. 



96. HYMENOPAPPUS L'Her. 



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

 nately divided leaves. Heads corymbose or rarely solitary, 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 mm. long, not over twice as long as the lobes. 

 Pappus over 1 mm. long, equalling the corolla-tube or nearly so. 

 Stem 3-6 dm. high, leafy throughout; heads numerous. 



Plant sparingly and loosely floccose; leaves glabrate in age. 1. H. tenuifolius. 

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

 Stem less than 3 dm. high. 



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



3. H. scaposus. 

 Stem-leaves not much reduced; stem sparingly grayish-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-tomentose; achenes silky. 4. H. arenosus. 

 Stem sparingly grayish-tomentose, 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.fiUfolius. 

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



mm. long. 7. H. luteus. 



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



lobes. 

 Pappus equalling 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; corolla-tube 3-4 mm. long; stem woolly 



at the base. 



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



Bracts yellow-tinged. 3. H. scaposus. 



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

 Stem leafy at least half its height, decidedly woolly at the base. 10. H. eriopodus. 

 Stem leafy only at the base, not conspicuously woolly. 11. H. 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 linear 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. N.M. Tex. Ark. 

 Plain. Je-S. 



