838 CARDUACEAE 



Rav-flowers fertile : achenes winged ; pappus-awns without inter- 

 "mediate squamellae. 77. Ximenesia. 



b. Achenes obcompressed ; paleae flat or hardly concave; involucres dis- 

 tinctly double. 

 Bracts of the involucres distinct or nearly so. 



Pappus in ours of small teeth, a mere border, or wanting. 



78. Coreopsis. 

 Pappus of 2-4 barbed or hispid awns. 79. BiDENS. 



Bracts of the Loner Involucre united at least to near the middle. 



80. Thelesperma. 

 2. Pappus of 5-many, linear to lanceolate squamellae with thickened axis and 

 hvaUne margins. 

 Rays fertUe; paleae of the receptacle thin and scarious; pappus-squamellae 



■fimbriate. 81. Ptiloxell.\. 



Rays sterile; paleae of the receptacle bristle-form; pappus-squamellae not 

 fimbriate. 110. Gaill.\rdia. 



B. Bracts of the invohicres uniserial, partly or wholly enclosing the achenes of the fer- 

 tile ray-flowers; plants glandular-\-iscid. 

 Achenes of the inconspicuous rays laterally compressed and enclosed in the con- 

 dupUcately infolded mvolucral bracts. 

 Disk-flowers several; corolla hairy; stout annuals with sessile or short-pedimcled 



heads. 82. Madia. 



Disk-flowers soUtary; coroUa glabrous; slender low annuals with small heads on 

 filiform peduncles. 83. H.\rp.'\£C.\rpus. 



Achenes of the ray-flowers with broad and rounded backs, or more commonly obcom- 

 DrcssGd. 

 Ligules of the ray-flowers minute; achenes completely invested by the whole 

 involucral bract; disk-flowers sohtary; heads small and short-peduncled. 



84. Henuzonella. 

 Ligules of the ray-flowers conspicuous; achenes enclosed in the basal portion of 

 the bracts, the dilated margins of which are abruptly infolded; disk-flowers 

 several or many. 

 Ray-flowers about 5, with deeply 3-cleft ligiiles; disk-flowers sterile, without 



pappas. 8.5. Lagophyll.\. 



Ray-flowers 8-20, with merely 3-lobed or toothed ligules; disk-flowers mostly 

 fertile with pappus of 5-20 bristles. 86. Blepharipappus. 



Tribe 7. HELENIAE. 



I. Ligules persistent and becoming papery on the striate achenes; plants more or less 



woollv. 

 Pappus of scales; rays 3-4, very broad; involucres of 4-10 coriaceous wooUy bracts. 



87. P.SILOSTROPHE. 



Pappus none; rays 5-50; involucres of numerous tliin herbaceous bracts. 



88. Baileya. 



II. Ligules deciduous or none. 



A. Achenes fiat with only marginal nerves; disk-corollas 4-toothed. 

 Pappus none or of a single bristle; bracts distinct; suffruticose plants. 



89. MONOTHRIX. 



Pappus of a lacerate-cUiate crown and sometimes with an additional pair of short 

 awns; bracts more or less connate; not suffruticose plants. 



90. Pericome. 



B. Achenes angled, not flat, nerved or striate. 

 1. Receptacle naked. 



a. Bracts of the involucres pale or colored, at least the margins and tips scari- 



ous. 

 Corollas of the disk-flowers with reflc.\ed or spreading lobes; bracts of the 

 broadly campanulate involucres obovate or broadly oblong. 

 Heads discoid. 96. Hymenopappds. 



Heads radiate; ligules obscurely toothed, yellowish or white. 



97. Leuc.ampyx. 

 Corolla of the disk-flowors with hn oar, erect lobes; bracts of the tiu-binate 

 involucres sjiat iilat(! to linear-oblanceolate in two series; ligules if pres- 

 ent deeply ckll, ])nn)le. 98. Oth.^KE. 



b. Bracts of the involucres neither colored nor scarious. 



Pappus of numerous barbellulate white bi istles, somewhat broadened and 

 united at the base into a ring. 104. Syntrichopappus. 



Pappas of scales or wanting. 



Achenes either linear-prismatic or clavate-obpyramidal, i. e., very 

 elongate. 

 Bracts more or less carinato-concave and partly enfolding the 

 achenes; leaves more or less floccose woolly. 

 Low and diffuse winter annuals; anther-tips subulate; bracts 

 herbaceous; tube of the disk-corollas equalling the throat. 



103. Antheropeas. 

 Perennials; anther-tips obtuse; bracts firm; tube of the disk- 

 corollas shorter than the tlu-oat. 102. Eriophyllum. 

 Bracts wholly herbaceous, broad and flat or merely concave, not 

 embracing the achenes; plants not floccose-lanate. 

 Foliage impressed-punctate ; leaves at least the lower opposite. 

 Perennials, suffruticose at the base; leaf-segments oblong to 

 linear. 91. PicRADENioPsrs. 



