COMPOSITE. 05 



Akenes thick, in the ray mostly 3-sided aud in the disk compressed, more or loss niar'j.iii> d, 

 without pappus, or sometimes with 2 to 4 teeth or short awns. Leaves oppo.-itr and heads 

 small. 



-f -i -t Bracts of the many-flowered receptacle concave or complicate, I.I;M Iv < 'min- 

 or subtending the disk-akenes, mostly persistent. 



H- Rays uniformly none, the flowers all hermaphrodite and fertile : involucre drv or pariiv 

 so : akeues not flat nor margined : pappus of slender awns or none, 



90. MELANTHERA. Involucre hemispherical; the disk in fruii globular, ami s(|i\-i, 

 with the mostly pointed rather rigid striate concave bracts of the cou\r\ or low-conical 

 receptacle; bracts of the involucre ovate to lanceolate, tliickish, nerveless, in -2 or :; seri.-.-:. 

 somewhat eijual in length. Corolla 5-lobed, with campanulate-oblong ampliatc throai. 

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

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

 more slender caducous awns. Leaves opposite, petioled. 



91. VARILLA. Involucre short, of rather few and small linear-lanceolate appivssed-inibri- 

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

 receptacle. Corolla with narrow cylindraccous throat, 5-toothed. St \le-hranclies with short 

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

 thin-walled, smooth, evenly 8-15-nerved : pappus setulose or none. Shnibhy or sun"nitico>e. 



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

 Corolla similar but small. Style-branches with subulate tips. Akeues 4-.Vanglcd, Mnall, 

 little compressed, destitute of pappus. Herbaceous. 



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

 pappus also wanting : these resemble Isocarpha. 



-H- -H- Hays present, but in several genera occasionally wanting: involucre commonly her- 

 baceous or foliaceous, or partly so. 



=r Receptacle high, from conical to columnar or subulate, at least iu fruit. (Here Gi/m- 

 nolomia, as to two species, would be sought.) 



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

 times peuicillate at tip: akenes small : leaves opposite. 



93. SPILANTHES. Involucre of a few somewhat herbaceous loosely appressed brans. 

 Bracts of the receptacle soft and chaffy, shorter than the flowers, more or less coiiduplicatc 

 and embracing the akeues, at length falling with them. Disk-corollas 4-5-toothed. Akeues 

 of the ray triquetrous or obcompressed ; those of the disk either moderately or much com- 

 pressed and with acute or nerve-like margins, sometimes ciliate-limbriate. 1'appus a 

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



b. Rays sterile (imperfectly styliferous in Echinacea, otherwise completely neutral), soon 

 drooping, sometimes marcescent, the ligule with very short tube or none : M\lc-l,ranches 

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



94. ECHINACEA. Involucre imbricated in 2 or 3 or more series and squarrose : its bracts 

 lanceolate. Disk at first only convex, becoming ovoid and the receptacle a.-nieh conical 

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

 acuminate into a rigid and spiuescent cusp, surpassing the disk-flowers. 



and pendent in age, rose-colored or rose-purple, marcescent, usually imperfe 

 Disk-corollas cylindraceous, with 5 erect teeth and almost no proper tube (a ring upon 

 which the stamens are inserted). Akenes suberose-cartilaginous, acutely quadrangular, 

 somewhat obpyramidal, with a thick eoronilorm pappus more or less ex 

 teeth at the angles ; the basal 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 chaffv bracts not spinescent, but sometimes soft-pointed. Ligules y,.|l,.w or partlj (rarely 

 wholly) 'brown-purple. Disk-corollas with a short but usually a manifest proper i 

 Akenes 4-angled, prismatic, in some species quadrangular-compressed, or n. one nearl; 

 terete. Pappus a coriaceous or firm-scarious and often 4-toothed crown, sometimes eep 

 and cupuliforni, sometimes obsolete, or none. 



5 



