COMPOSITJE. 65 



Akenes tliirk. in the rar mostlv 3-sided and in the di~k compressed, more or less margined, 

 without pappus, or ^umetimes witli i to 4 teeth or .-hurt awns. Leaves opposite and hea.is 

 Muall. 



•*— -J— -*— Br;Kts of the many-floivered receptacle concave or complicate, luosely emhracitu' 



or subtending the disk-akeues, m.jstk per^i^tLiit. 

 ++ Eays uniformly none, the flowers all hermaphrodite and fertile : involucre drj or partly 



so : akeues not flat nor margined ; pappus of .-leuder awns or none. 



90. MELANTHERA. Involucre henli^Illlurical; the disk in fruit globular, and squarrose 

 with the mostly pointed rather rigid striate concave brart< of the convex or low-conical 

 receptacle; bracts of the involucre ovate to lanceolate, thickish, nerveless, in 2 or 3 series, 

 somewhat equal in length. Corolla 5-lobed, with campauulate-oblong ampliate throat. 

 .Style-branches tipped with a subulate hispid appendage. .Vkenes thick and short, com- 

 pressed-quadrangular, somewhat obpyramidal, with broad truncate summit : pappus of 2 or 

 more slender caducous awns. Leaves opposite, petioled. 



91. A^ARILLA. Involucre shurt, of rather few and small linear-lanceolate appresseil-imbri- 

 cate and mostly few-striate bracts, similar to those of the at length high-conical or obloii? 

 receptacle. Corolla with narrow cyhndraceous throat, .5-tuMthed. St\"le-branches with slii.-rt 

 and obtuse or minutely apiculate conical tips. Akenes narrow-, linear-oblong, terete, rather 

 thin-walled, smooth, evenly S-15-nerved: pappus settilijs^- or none. >hrubbv or suffruticose. 



92. ISOCARPHA. Involucre, receptacle, and dry Lracts nearly of the preceding genus. 

 Corolla similar but small. Style-branches with subulate tips. Akeues 4-5-angled, small, 

 little compresseil, destitute of pappus. Herbaceotis. 



93. SPILANTHES. Some (exotic) species have no ray -flowers, and akenes not flat, mth 

 pappus also wanting : these resemble hucarpha. 



+-i- -H- Rays present, but in several geuera occasionally wanting: involucre commonlT her- 

 baceous or foliaceuus, or partly so. 



= Receptacle high, from conical to columnar or subulate, at least in frtiit. (Here Gym- 

 nohmia, as to two .-pecics, would be sought. ) 



u. Eays fertile, or not rarely wanting : style branches of the disk-flowers truncate and some- 

 times peniciUate at tip : akenes small ; lea", es oppusitc. 



93. SPILANTHES. Involncre of a few somewhat herbaceous loosely appressed lirarts. 

 Bracts of the receptacle soft aud chaffv, shorter than the flowers, more or less conduplicate 

 and embracing the akenes, at length falliog with them. Disk-corollas 4-5-toothed. Akenes 

 of the rav triquetri.'its or obcc'Uijiresseil ; those of the disk either moderately or much com- 

 pressed and with acute or nerve-like margins, sometimes ciliate-fimbriate. Pappus a 

 setiform awn from one or more of the angles, or none. 



6. Ravs sterile (imperfectly styliferotis in Echinacea, otherwise completely neutral), soon 

 drooping, staiieiimes marcescent, the ligule with very short tube or none; style-branclies 

 tipped with an acute or obtuse hispid appendage ; leaves mostly alternate. 



94. ECHINACEA. Involucre imbricated in 2 or 3 or more series and sijnarrose; its bracts 

 lanceolate. Disk at first only convex, becoming ovoid and tlie receptacle acutely conical. 

 Chaffv bracts of the latter firm and completely persistent, linear-lanceolate, carinate-concave, 

 acuminate into a rigid and spiuesceijt cusp, surpassing the disk-flowers. Ligules elongated' 

 and pendent in age. rose-colored or rose-pnrple, marcescent, usually imperfectly styliferous. 

 Disk-cor'llas cylindraceous, with 5 erect teeth and alni'jst no proper tube (a ring upon 

 which the stamens are inserteilj. Akenes suberose-cartOagiuiiU?. acutely quadrangtilar, 

 somewhat obpyramidal, \vith a thick coroniform pappus more or less extended into triangular 

 teeth at the angles : the bas.tl areola central. 



95. RUDBECKIA. Involucre looser, spreading, more foliaceous. Disk from hemispheri- 

 cal or globose to columnar, and receptacle from acutely conical to cylindrical and subulate; 

 its chafiv bracts not spiuescent, but sometimes soft-pointed. Ligules yellow or partly (rarely 

 whollv) broivn-purple. Disk-c ti illas with a short but usually a manifest proper tube. 

 Akeues 4-angled, prismatic, iu some species quadrangulaT<ompressed, or in one nearly 

 terete. Pappus a coriaceous or firm-scariijus and often 4-toothed crown, sometimes deep 

 and cuptiliform, sometimes obsolete, or none. 



5 



