230 CARDUACE.\E 



Corolla of the disk-flowers with hnear, erect lobes; bracts oftlie turbinate 

 involucres spatulate to liuear-oblanceolate in two series ; Ugules if pres- 

 ent deeply cleft, piu-ple. 98. Othake. 

 b. Bracts of the mvolucres neither colored nor scarious. 



Pappus of numerous taarbellulate white bristles, somewhat broadened and 



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



Pappus of scales or wanting. 



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

 elongate. 

 Bracts more or less carinate-concave and partly enfolding the 

 achenes: leaves more or less floccose woolly. 

 Low and diffuse whiter amiuals; anther-tips subulate; bracts 

 herbaceous; tube of the disk-coroUas equalling the tliroat. 



103. AN'THEROPEAS. 



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

 corollas shorter than the tliroat. 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. Picr.vdeniopsis. 



Annuals; leaf-segments filiform or nearly so. 



95. Cephalobembdc. 

 Foliage not impressed-punctate; leaves alternate. 

 Bracts obovate, cuneate or oblanceolate. 



Perennials with a woody caudex; leaves entire: pappus of 



10 squamellae. 93. Pl.\tyschkuhria. 



Annuals; leaves dissected; pappus wanting. 



92. Amauriopsis. 

 Bracts linear. 



Bracts in one row or two subequal rows; plant not fleshy: 

 achenes linear. 

 Heads radiate, but h gules inconspicuous; pappus of 



opaque squameilae. 99. Rigiopappds. 



Heads discoid; pappus of hyaUne squamellae. 



Achenes angled; squamellae with strong midribs. 



100. CH.ViL\ECHEX.\CTIS. 



Achenes scarcely angled: squamellae not conspicu- 

 ously ribbed. 101. Ch.\ex.\ctis. 

 Bracts in 2-3 rows; heads radiate; leaves more or less 

 fleshy. 94. Hulsea. 

 Achenes obpyramidal, not 4 times as long as broad. 



Bracts of the involucres erect, not spreading nor reflexed. 



Involucres manj- -flowered ; pappus present; achenes tapering 

 below. 

 Bracts of the involucres nearly equal and similar, all distinct. 

 Bracts few; corolla flesh-colored; rays wanthig. 



100. CH.\NLVECHAEXACTIS. 



Bracts numerous; corollas yellow; rays usually present. 

 Leaves entire; squamellae short, obtuse or abruptly 



contracted into a point. 105. Tetraneuris. 

 Leaves pinnatifld; squameUae linear-lanceolate, at- 

 tenuate but not awn-tipped. 



106. Rydbergia. 

 Outer bracts united below; leaves usually pinnatifld with 

 narrow divisions. 107. Hymenoxys. 



Involucres few-flowered; pappus wanting: achenes Ihiear, 8-10- 

 striate. 108. Flaveria. 



Bracts of the involucres spreaduig or reflexed. 



Leaves not decurrent on the stem; tubes of the disk-flowers 



moderately long. 109. Dugaldia. 



Leaves decurrent on the stem; tubes of the disk-corollas very 

 short or reduced to a ring. 110. Helexium. 



2. Receptacle with bristle-like chaffs. 



Involucral bracts spreading or reflexed. 111. Gaill.\rdi.\. 



Involucral bracts erect. 101. Chaen.\ctis. 



Tribe 8. TAGETEAE. 

 Bracts of the involucres more or less miited; style-branches of the disk-flowers elongate 

 Bracts of the involucres united only at the base; style-branches with conical tips. 



squamellae of the pappus niany-aristate. 112. Boebera. 



Bracts of the involucres united into a cup: style-branches obtuse. 



113. Thi-jiophylla. 

 Bracts of the involucres distinct: style-branches very short, obtuse, without an appendage. 



114. Pectis. 

 Tribe 9. ANTHEMIDEAE. 



Receptacle chaffy. 



Achenes flattened; involucres campanulate or obovoid, small; ligules short and broad. 



115. Achillea. 

 Achenes terete, at least not flattened; involucres hemispherical, large: ligules elongate. 



Ray-flowers fertile; paleae of the receptacle membranous, subtending all the 

 flowers. lit). A.VTHE.viis. 



