66 COMPOSITE. 



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

 winged at one or both edges, somewhat laterally or obliquely inserted on 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 akenes, 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 : akenes not winged nor 

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



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

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

 pappus persistent or none. 



97. WEDELIA. Akenes 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 

 and foliaceous. Leaves opposite : stem herbaceous. 



98. BORRICHIA. Akenes 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 herbs. 



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 squamellse, commonly produced at one or more of the 

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

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

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

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



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

 but none margined or winged ; those of the ray inane or sterile : chaffy 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 tube of which 

 is usually pubescent. 



1 03. VIGUIERA. Pappus of two chaffy awns or paleze, one to each principal angle of the 

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

 truncate palese or squamellas on each side, either persistent or deciduous. Akenes commonly 

 pubescent. Peduncles slender. 



1 03. TITHONIA. Pappus of Viguiera or more persistent : habit of the annual species of 

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

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

 the head. 



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

 what awned paleas, mostly no intermediate squamellaa or palete, except sometimes as de- 

 tached or partly united portions of the principal palese. 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 either 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- 



