coMrosiTJo. 293 



* Rcceptnrle plongjited, l)econung columnar. 



43. Rudbeokia. Rays neutral, or very rarely none. Akenes quadrangular and compressed. 



• ♦ Receptacle flat, convex, or rarely conical. 

 +- Rays pistillate and fertile. 



44. Balsamorhiza. Pappus none. Akenes of the ray obcompressed, of the disk prismatic- 



ipiadrangular or somewhat compressed. 

 4.5. Wyethia. l'ai)pus a chaffy-roriaceous crown or cup, continuous with the broad summit of 



the prismatic-qiiadrangular or compressed akeno, persistent, irregularly cleft into 6 or 



morn lohcs or Icetli, those on the angles Bomctimes olongateil into rigid cliafTy awns. 

 4(). Verbeslna. Pa})pus 2 slender or small awns ; the ilat akeiic margined by a broad wing, at 



least in the disk -flowers. 



-1- +- Rays neutral, or rarely none. 



47. Encelia. Akenes flat and fbin-edged but marginlcss, strongly villous-ciliate : pappus none 



or a pair of awns, but no intermediate little scales. 



48. Helianthella. Akenes flat and the thin edges more or less margined : pappus a pair of per- 



sistent awns or chafTy teeth, and a crown of intermediate (sometimes very minute) thin 

 cbafTy scales. 



4n. Helianthua. Akenes thick, quadrangular-compressed or with the si,dcs convex, the edges 

 obtuse ; pappus a pair of caducous chaffy scales or awns. Receptacle flat or merely 

 convex. 



50. Viguiera. Akenes of Helianthiis : pappus with chaffy scales between the awns. Recepta- 

 cle convex or conical. 



Subtribe III. COREOPSIDEiE. Heads as in the preceding subtribe, except that the chafT 

 of the receptacle is flat or barely concave, and mostly deciduous with the fruit. Akenes all 

 obcompressed, i. e. flattened parallel with the subtending scales of the involucre and chaff 

 of the receptacle : pappus of 2 to 4 awns or tooth from the angles, or none. Involucre in 

 our gejiora double, tlio outer looso and more or less foliaccouH. 



fil. PuglopappUB. Rays pistillate, perhaps sometimes neutral. Akenes long-villous or ciliate : 

 pappus of 2 large and bayonet-shaped naked chaffy awns. 



r)2. Leptosyne. Rays pistillate. Akenes naked, winged or margined : pappus none or a mi- 

 nute cup. 



.53. Bidens. Rays neutral or none. Pappus of 2 to 4 rigid retrorsely barbed awns. 



Subtribe IV. GALINSOGE^. Heads, &c., as in snbtribes IT. and V. Akenes neither com- 

 pressed nor obcompres.sed. Pappus in both ray- and disk-flowers of numerous chaffy scales 

 or awns (rarely nearly none). See one exceptional I{cmizonia, No. 57. 



54. Blepharipappus. Head rather few-flowered ; the rays pistillate. Akenes turbinate ; pap- 



pus of 12 to 20 narrow and thin cut-fringed scales having a strong midrib, occa.sionally 

 nearly or wholly wanting. 



Subtribe V. MADIE/E. Heads heterogamous, with ray-flowers fertile ; those of the disk 

 either perfect and fertile or sterile ; rarely the ray-flowers wanting. Involucre a series of 

 scales, each enclosing more or less a ray-akene, sometimes a few outer and empty or 

 bracteal scales. Receptacle chaffy only at the margin, the chafT forming a sort of interior 

 involucre, or else subtending either some or all of the disk-flowers. Style-branches of the 

 latter teiTninated by a subulate hispid tip. Pappus none for tlie ray-akenes (or abnor- 

 mally some rudiments in a few cases), composed of several awns or chafl'y scales or else none 

 in the disk-flowers. Herbs mostly glandular nnd viscid, and heavy-scented : upper leaves 

 alternate, the lower or lowest opposite. 



* Akenes all laterally compressed, those of the ray wholly en<'losed in the carinato strongly in- 



folded scales of the invohicri', which therefore l>ecomes deeply sulcjit^. 



55. Madia. Pappus none, or of some small scales in the sterile flowers of one section. 



♦ » Ray-akenes turgid, more or less oblique or incurved, never laterally compressed, but mostly 



rather obcompressed ; the investing scales of the involucre rounded on the Iwick. 



50. Hemlzonella. Involucre strongly 4- C-.suleafo (in tlio mnnner of ilA^f/iVr) by the rompleto 

 enwrapping of the 4 or 5 akenes. Disk-flower one, fertile, in a sort of interior involu- 

 cre : pnppus none. 



57. Hemizonia. Involucre many- few-flowered, less if at nil sulcnte or lolled ; its scales at 

 base half-enclosing the obovnto or .somewhat triangular i-ay-nkenes. Disk-flowers numer- 

 ous or few, all or some of thetn infertile : pappus of chaffy scales or non**. 



