SYNG12NESIA. 225 



ceptacle naked (or downy, Sm,). Florets of the ray subulate. 

 Pericarps crowned with a membranaceous pappus. 



(Ttissilago Farfara and Injhrida. Sect. *'^.) 



** Radiati. Corollas of the ray ligulate. 



32. Bei.lis. /;zyo/Mcre hemisphserical, its scales equal. Recep- 

 tacle naked, conical. Pappus none. 



35. Matricaria. Involucre heniisphaerical or almost plane, 

 imbricated with scales whose borders are membranous. Re- 

 ceptacle naked, almost cylindrical. Pappus none. 



33. Chrysanthemum. Involucre hemispha;rical, imbricated with 

 scales whose borders are membranous. Receptacle naked. 

 Pappus none. 



34. Pyrethrum. Receptacle heniisphaerical, imbricated with 

 scales whose borders are membranous. Receptacle naked. 

 Pericarps crowned with a membranous margin. 



31, DoRONicuM. Scales of the irivolucre in two equal rows, 

 longer than the disk. Receptacle naked. Pericarps of the 

 disk crowned with a simple pappus, those of the ray without a 

 pappus, 



30. Inula. /;zyo/z/cre imbricated. Receptacle naked. Florets 

 of the ray very numerous, linear. Anthers with 2 bristles at 

 the base. Pappus sometimes simply composed of hairs, some- 

 times double; the ex/, membranous. 



25. Erigeron. Involucre imbricated. Receptacle naked. Flo- 

 rets of the ray numerous, very narrow (mostly of a different 

 colour from the disk). Pappus simple. 



29. SoLiDAGO. Involucre imbricated, its scales connivent. 

 Receptacle naked. Florets of the ray (of the same colour 

 as the disk) about 5. Pappus rough. 



28. Aster. Involucre imbricated, its lowermost scales spread- 

 ing (except in A. iripoUum). Receptacle naked. Florets of 

 the ray more than 10. Pappus simple. 



27. Senecio. Involucre subcylindrical, equal, scaly below j the 

 scales withered at the tip. Receptacle w^ked. Pappus s\m\)\e. 



26. TussJLAGO. Invohicre simple, equal, submembranaceous, 

 swelling. Receptacle naked. Pappus simple. 



36. Anthemis. Livolucre heniisphaerical ; its scales nearly 

 equal, their margins scariose. Receptacle convex, chaffy. 

 Pericarps crowned with a membranous border or pappus. 



37. Achillea. Involucre ovate, imbricated, unequal. Re- 

 ceptacle plane, chaffy. Florets of the ray 5 — 10, rouudi&hr 

 obcordate. Pericarps ndked. ^ ;,';;.!' 



(Bidens cernua. .Ord; I. Sect. ***,) /'"•'. 



