COMPOSITE 49 



varies from plane to conical, or oblong, or even cylindrical or subulate. When the 

 receptacle bears flowers only, it is naked, although the surface may be alveolate, 

 foveolute, or merely areolate, according as the insertion of the ovaries or akenes 

 is surrounded or circumscribed by honeycomb-like or lesser elevations ; or, when 

 these project into bristles, slender teeth, or shreds, it h JimhriUate : it h paleaceous 

 when the disk-flowers are subtended by bracts ; these usually chaff-like, therefore 

 called palece, chaff, or simply bracts of the receptacle. In place of calyx-limb 

 there is more commonly a circle of epigynous bristles, hairs, or awns, the pappus, 

 a name extended to the calyx-limb of whatever form or texture : its parts are 

 bristles, awns, paleiB, teeth, &c., according to shape and texture. Corollas either 

 all tubular (usually enlarging above the insertion of the stamens into the throat, 

 and 4-5-lobed at summit, mostly regular) ; or the marginal ones strap-shaped, 

 i. e. ligulafe, the elongated limb (ligule) being explanate, and 3-5-toothed at the 

 apex. Such are always female or neutral, or, when all the flowers of the head 

 have ligulate corollas, then hermaphrodite. Anthers with basal auricles either 

 rounded or acute, or sometimes produced into tails (caudate). Branches of the 

 style in female flowers and in some hermaphrodite ones margined with stigma, 

 i. e. stigmatic lines, quite to tlie tip ; in most hermaphrodite flowers these lines 

 shorter, occupying the lower portion, or ending at the appendage or hairy tip. 

 — An immense oriler, comprising a tenth part of known pha;nogamous plants, an 

 eighth of those of North America. 



Key to the Tribes. 



Ser. I. TuBULiFLOR^. Corollas tubular and regular in all the hermaphrodite 

 flowers. 



Heads homogamous and discoid : flowers all hermaphrodite and never j^ellow : anthers 

 not caudate at base. 



Style-branches elongated filiform-subulate, hispidulous throughout ; stigmatic lines 

 only near the base : leaves alternate I. VERNONIACEiE. 



Style-branches elongated, more or less clavate-thickened upward and obtuse, minutely 

 papillose-puberulent, stigmatic only below the middle. II. EUPATORIACEiE. 

 Heads homogamous or heteroganious, discoid or radiate : flowers not rarely yellow : 

 style-branches of hermaphrodite flowers with stigmatic lines mostly proniiiudous 

 and extending either to tlie naked summit or to a more or less distinct pubescent 

 or hispidulous tip or appendage. 



Anthers not caudate at base : style-branches in hermaphrodite flowers flattened and 

 with a distinct (but sometimes very short) terminal appendage : disk-corollas gener- 

 ally yellow : rays of same or difl'erent color III. ASTEROIDE^. 



Antliers caudate : style-branches of hermaphrodite flowers slender, destitute of any 

 terminal appendage, the stigmatic lines extending quite to (or vanishing near) the 

 naked obtuse or truncate sununit : leaves alternate: heads in our genera discoid 

 except in /««/« IV. INULOIDEiE. 



Anthers not caudate : style-branches with truncate or variously appendiculate pubes- 

 cent or hispid ti])s : involucre not scarious : receptacle paleaceous, i. e. with chafi'y 

 bracts subtending at least the outer disk-flowers : pappus various or none, never of 

 fine capillary bristles V. HELIANTHOIDEiE. 



Anthers not caudate : receptacle naked : pappus from paleaceous to setiform or none : 

 herbage often punctate with resinous or pellucid dots or glands : otherwise nearly 



as preceding VI. HELENIOIDEvE. 



4 



