96 COMPOSlTiE. Asteroidej:. 



25. Sericocarpus. Pappus simple, unequal. Flowers of the ray and disk few. 

 Involucre oblong, imbricated, cartilaginous. 



2G. Aster. Pappus simple, copious. Rays numerous, in a single series. Invo- 

 lucre more or less imbricated. Keceptacle alveolate. 



27. Erigeron. Pappus either simple (not copious), or double; the exterior seta- 



ceous-subulate or squamellaie. Kays very numerous, and often in 

 two or more series, fccales of the involucre nearly equal, almost in a 

 single series. Keceptacle naked. 



28. DiPLOPAPPUs. Pappus double ; the exterior short and setaceous or squamel- 



late-subulate. Kays in a single series. Involucre imbricated. 



* * * Pappus of the ray and disk dissimilar. 



29. TowNSENDiA. Pappus simple ; that of the disk composed of subulate-capil- 



lary bristles; of the ray short and subulate. Achenia compressed. 



30. Ch.etopappa. Pappus double; the inner of 5 rigid bristles; the exterior oC 



1 to 5 hyaline scales. Achenia nearly terete. 



31. BoLTONiA. Pappus of several very small, and 2 or more rigid and subulate 



larger bristles. Achenia flat, margined. 



Siibdiv. 2. Bellide^;. — Pappus none, or minute and coroniform. 



32. Bellis. Achenia obovate, compressed. Pappus none. 



33. Aphanostephus. Achenia terete. Pappus a very minute crown. 



Subdiv. 1. EUASTERE.E. — Pappus, at least the inner, composed of capillary 

 or rarely subulate bristles. (Euastereee, Diplopappefe, Erigereae, & Heteropap- 

 peee, DC.) 



22. GALATELLA. Cass. diet. 37.;?. 4G3 ; Nees, Ast. p. 158. (excl. spec.) 

 Galatea, Cass. {(lid. 18, tf-c.) ; Less. 

 Heads many-flowered ; the ray-flowers ievr (3-12), sterile, but u.sually 

 furnished with a rudimentary style, and sometimes with one or two abortive 

 filaments ; those of the disk tubular, perfect. Involucre shorter than the 

 disk ; the scales closely imbricated in 3 or 4 series, sometimes obscurely 1-3- 

 nerved or slightly carinate, destitute of herbaceous tips; the outermost 

 bracteolate. Receptacle alveolate, the alveoli toothed. Corolla of the disk 

 with a cylindrical tube, and an expanded deeply 6-cleft limb ; the lobes lan- 

 ceolate-linear, spreading. Anthers ex.serted. Branches of the style (in the 

 disk-flowers) linear, terminated by a short and broad deltoid-spatulate or tri- 

 angular appendage. Achenia oblong or slightly cuneiform, somewhat com- 

 pressed, silky-villous. Pappus composed of copious rather rigid unequal 

 serrulate-scabrous capillary bristles ; that of the ray similar but rather 

 shorter. — Perennial herbs (natives of Europe, Northern Asia, and the United 

 States); the stems simple below, corymbose at the .summit. Leaves alter- 

 nate, lanceolate or linear, entire, rather rigid, 1-3 nerved, veinless, often 

 impressed-punctate. Heads terminating the fastigiate branches. Rays blue, 

 purple, or nearly white ; the disk-flowers yellow, sometimes changing to 

 purplish. 



Galatella scarcely differs from Linosyris except by the presence of (white or blue) 

 rays ; and these, according to Ledebour, are sometimes wanting in G. dracunculoi- 



