66 COMPOSITE. 



96. LEPACHYS. Akeues short and broad, compressed, acutely margined or sometimes 

 winged at one or both edges, somewhat laterally or obliquely inserted ou the slender- 

 subulate receptacle : pappus a chaffy or aristiform tooth over one or both edges, or none, 

 the crown minutely squamellate and evanescent or none. Chaffy bracts of the receptacle 

 conduplicate or deeply navicular, with thickened and truncate or somewhat hooded sum- 

 mit, embracing and hardly surpassing the akeues, at length deciduous with them. Corollas 

 of the disk with hardly any proper tube. Ligules, involucre, &c., of Rudbeckia. 



= == Receptacle from flat to convex, or in certain species conical : akeues not winged nor 



very flat, when flattened not margined or sharp-edged. 

 a. Rays fertile : style-branches of tiie disk-flowers hispid for all or much of their length : 



receptacle flat or merely convex : ray akeues commonly triquetrous or obcompressed : 



pappus persistent or none. 



97. WEDELIA. Akeues thick and turgid, cuneate-oblong or pyriform, with roundish sum- 

 mit; those of the disk obtusely if at all quadrangular, or flattened only at the inane base: 

 pappus a paleaceous commonly lobed and at length indurated cup. Involucre rather simple 

 aud foliaceous. Leaves opposite : stem herbaceous. 



98. BORRICHIA. Akeues equably and acutely quadrangular, or in the ray triangular : 

 pappus a somewhat toothed cup or crown. Involucre imbricated ; outer bracts sometimes 

 foliaceous. Bracts of the receptacle concave, rigid. Leaves opposite : stem woody. 



99. BALSAMORRHIZA. Akenes destitute of pappus, oblong ; of the disk quadrangular 

 and often with intermediate nerves (these and the angles usually salient). Ligules with a 

 distinct tube. Involucre broad ; the outer bracts foliaceous, sometimes enlarged. Bracts of 

 the receptacle linear-lanceolate. Style-appendages filiform or slender-subulate. Tuberous- 

 rooted low her1)s. 



100. WYETHIA. Akenes prismatic, large, 4-angled, or in the ray 3-angled and in the disk 

 often flattened, also with intermediate salient nerves : pappus a lacerate chaffy or coriaceous 

 crown, or cut into nearly distinct squamelbe, commonly produced at one or more of the 

 angles into chaffy rigid awns or teeth. Involucre campanulate or broader, more or less 

 imbricated ; outer bracts often foliaceous. Bracts of the receptacle lanceolate or linenr, 

 partly embracing the akenes. Style-appendages slender-subulate or filiform, very hispid. 

 Thick-rooted and large-headed herbs, with alternate leaves. 



h. Rays sterile, rarely wanting : akenes quadrangular-compressed or more turgid, or flatter, 

 but none margined or winged ; those of the ray inane or sterile : chaffj^ bracts of the 

 convex or conical receptacle either strongly concave or conduplicate and embracing the 

 akenes : leaves either opposite or alternate. 



101. GYMNOLOMIA. Pappus none or a minute denticulate ring; the truncate apex of 

 the short akenes commonly at length covered by the base of the corolla, the tul)e of which 

 is usually pubescent. 



102. VIGUIERA. Pappus of two chaffy awns or paleiE, one to each principal angle of the 

 akene, or occasionally one or two more, and of two or more intermediate shorter commonly 

 truncate paleaj or squamellse on each side, either persistent or deciduous. Akenes commonly 

 pubescent. Peduncles slender. 



103. TITHONIA. Pappus of F/^w/era or more persistent : habit of the annual species of 

 Helianthiis : involucre somewhat peculiar, of about two series of bracts, with appressed 

 and rigid usually striate base aud loose foliaceous tip. Peduncles clavate aud fistular under 

 the head. 



104. HELIANTHUS. Pappus promptly deciduous, of two scarious and pointed or some- 

 what awned palete, mostly no intermediate squamella; or paleic, except sometimes as de- 

 tached or partly united portions of the principal paleas. Akenes usually glabrous or 

 glabrate. Proper tube of disk-corollas short, and the throat cylindrical and elongated. 



= ==== Receptacle flat, convex, or sometimes becoming conical : akenes (of the ray or 

 margin often triquetrous) of the disk cither flat-compressed and margined or thin-edged, 

 or if turgid some of them winged : pappus not caducous. 



a. Truly shrubby, rayless, alternate-leaved : akenes wingless. 



105. FLOURENSIA. Rays none in the Mexican (several and neutral in the Chilian) 

 species. Involucre of 2 or 3 series of oblong or lanceolate bracts, at least the outer herba- 



