COMPOSITJE. 49 



varies from plane to conical, or oblong', or even cylindrical or subidate. "U'hen the 

 receptacle bears flowers only, it is nuk^d. althou-h the surface may be alveolate, 

 foreolate. or merely areolate. a.xording as the insertion of the ovaries or akenes 

 is surrounded or circumscribed by honeycomb-like or lesser elevation- ; or. when 

 these project into bristles, slender teeth, or shreds, it i> fimbriUate : it is paleaceous 

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

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

 there is more commonly a cii-cle of epigynous bristles, hairs, or awns, the pappus, 

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

 bristles, aiwns. pales, teeth, cVc, 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 (Jigule) 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 the tip ; in most hermaphrodite flowers these lines 

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

 — An i mm ense order, comprising a tenth part of known phsenogamous plants, an 

 eighth of those of Xorth America. 



Key to the Tribes. 



Ser. I. TuBULiFLOR-i;. Corollas tubular and regular in all the hermaphrodite 

 flowers. 



Heads honiogamous and discoid : flowers all hermaphrodite and never yellow : anthers 

 not caudate at base. 



Style-liraiiches elongated filiform-subulate, hispidulous throughout ; stigniatic lines 

 only near the base : leaves alternate I. ATENOXIACEj;. 



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

 papiUose-puberulent, stigmatic only below the middle. II. EUPATORIACEji. 

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

 style-branches of hermaphrodite flowers with stigmatic lines mostly prominulous 

 and extending either to the 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 : ray? of same or dilt'crfnt color. . ... III. ASTEROIDE^E. 



Anthers caudate ; style-branches of hermapfirodite flowers slender, destitute of any 

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

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

 except in Inula IV. IXULOIDEJE. 



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

 cent or hispid tips : involucre not scarious : receptacle paleaceous, i e. with chafiy 

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

 fine capillary bristles T. HELIAXTHOIDEJ. 



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

 herbage often punctate with resinous or pellucid dots or glands : othernT^e nearly 



as preceding " TI. HELEXIOIDE^". 



4 



