838 CARDUACEAE 



Ray-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 involucras distinct or nearly so. 



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



> 78. Coreopsis. 



Pappus of 2-4 barbed or hisj)id awns. 79. Bidens. 



Bracts of the inner involucre united at least to near the middle. 



^ _ ^ 80. Thelesperma, 



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



hyaline margins. 

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



fimbriate. 81. Ptiloxell.4. 



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

 T> T. . ^ , fimbriate. 110. Gaillardia. 



«. isracts of the involucres uniserial, partly or wholly enclosing the achenes of the fer- 

 tile ray-flowers; plants glandular- viscid. 

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



duplicately infolded involucral bracts. 

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



heads. 82. Madia. 



JJisk-flowers sohtary; corofla glabrous; slender low aimuals with small heads on 

 A u filiform peduucles. 83. Harpaecarpus. 



Acnenes of the ray-flowers wath broad and roimded backs, or more commonly obcom- 

 pressed. 



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

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



T . , ^ ^, « 84. HEAflZOXELLA. 



ijigules 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 Ugules; disk-flowers sterile, without 

 . pappus. ^ . , 85. Lagophyll.\. 



Ray-flowers 8-20. with merely 3-lobed or toothed Ugules; 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 



woolly. 



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



87 PsiLjOstropttf 

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



TT T.-nr,,!^ A -^ ^- Baileya. 



Xi. l^igules deciduous or none. 



A. Achenes flat with only marginal nerves; disk-coroUas 4-toothed 



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



T> ^ , ., 89. MONOTHRIX. 



i'appus of a lacerate-cihate crown and sometimes with an additional pair of short 

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



T( A 1. , , ^ 90. Pericome. 



13. 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. 



CoroUas of the disk-flowers ^ith reflexed or spreading lobes; bracts of the 



broadly campanulate involucres obovate or broadly oblong. 

 Heads discoid. 96. Hymenopappus. 



Heads radiate; hgules obscm-ely toothed, yellowish or white. 



i^ 11 ^ .X- J. , ^ 9'^- Leucampyx. 



corofla of the disk-flowers with linear, erect lobes; bracts of the turbinate 



mvolucres spatulate to linear-oblanceolate in two series; hgules if pres- 

 ent deeply cleft purple. 98. Othake. 



0. .Bracts of the mvolucres neither colored nor scarious. 



Pappiis of numerous barbell ulate white biistles, somewhat broadened and 

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



Pappus of scales or wanting. 



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



Bracts more or less carinate-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-coroUas equalling the throat. 



^ . - ^^ 103. AnTHEROPE.\S. 



Perenmals; anther-tips obtuse; bracts flrm; tube of the disk- 

 corollas shorter than the throat. 102. Eriophyllum. 

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



embracmg the achenes; plants not floccose-lanate. 

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

 Perenmals. suffruticose at the base; leaf-segments oblong to 

 toear. - 91. Picradexiopsis. 



