286 THE COMPOSITE EAMILT. 



("Florets all ligulate (LiGDLATES) SB 



, 1 Florets all tubular • • : ■ ^ 



) Florets tubular in the disk or centre of each head, the outer ones either ligulate 



L and forminp; a ray, or slender and filiform (Corymb rFEKs) 5 



^Involucre or leaves prickly. Style slightly bulbous under the branches (Thistle- 

 2] HEADS) '. 29 



(.Involucre and leaves not prickly 3 



„ ("Florets purple, blue, or white 4 



\ Florets yellow or greenish, usually small (CoETMBIFEEs) 5 



.f Leaves opposite 1- EfPATOBT. 



t Leaves alternate or radical (Thistleheads) 29 



C0E"5nviBIFEES. 



r ( Leaves opposite 6 



( Leaves alternate or radical 7 



„ ("Flower-heails small, numerous, purple. Pappus of many hairs . . 1. Eupatobt. 



(, Flower-heads few, rather large, yellow. Pappus of a few bristles . . 19. Bidens. 



f Flower discoid, that is, all the florets of the head tubiilar or filiform, the outer not 



« J longer than the central ones 8 



' I Flowers radiate, the outer florets ligulate and spreading, or, if erect, longer than the 



L central ones 18 



Q ("Achenes without a pappus, or crowned by a small cup or short scales .... 9 



(^Aehenes bearing a pappus of hairs 12 



("Flower-heads raonoeeious, the males with many tubular florets, the females forming 

 9-< a thick burr, ending in 2 conical beaks, and enclosing 3 flowers . 20. Bukweeh. 



(.Flower-heads aU alike - 10 



{Receptacle bearing scales between the florets. Plant covered with a dense white 

 cotton. Leaves entire or toothed 13. DiOTis . 

 No scales between the florets. Leaves, at least the lower ones, much divided . 11 



/"Flower-heads hemispherical, 3 or 4 lines in diameter, in a large terminal corymb. 



-.-. 1 Achenes angular, with a flat top 14. Tanst. 



i-plower- heads small, often nodding, in a leafy raceme or panicle. Achenes obovate, 



(^ contracted at the top 15. Artemisia. 



-.„ r Bracts of the involucre linear, equal in length, with a few very small outer ones . 13 



I Bracts of the involucre imbricated in two or more rows 14. 



("Eadieal leaves large, broadly heart-shaped or orbicular. Stem-leaves smnU and 

 13 ■< narrow 2. Coltsfoot. 



(.Leaves pinnate and toothed 17. Sknecio. 



f Plants more or less covered with a white cotton or down. luvolucral bracts also 

 14< cottony, or shining and searious, or coloured at the edge ... 16. Codweed. 



[ Plants not woolly. Involucral bracts narrow and green 15 



f All the florets tubular and 5-toothed 16 



15^ Outer florets of the head linear or filiform, although not longer than the central 



(^ oness. 17 



rlnvolucrahferacts few, oblong-linear. Plant growing in salt-marshes . .3. Asteb. 

 16 1 Involucral bracts numerous, narrow-linear. Plant growing on limestone rocks. 



\_ 5. LiNOSTEIS. 



-_<" Tall stifi" plant. Flower-heads ovoid, in a terminal corymb ... 7- ifi//irf Inule. 



' t Flower-heads numerous and small, in a long leafy panicle 4. Canadian EfiiaEBON. 



..Q ("Achenes without any pappus, or crowned by a small cup or minute scales . . . 19 



\ Achenes bearing a pappus of hairs 2.S 



, „ f Receptacle bearing scales between the florets, at least among the central ones . . 20 



t Receptacle naked (without scales between the florets) 21 



„„(■ Flower-heads rather large, with a convex or conical receptacle . . 11. Camomile. 



\ Flower-heads small, with a small flat receptacle 12. Achillea. 



„, f Involucral bracts all green and of equal length 8. Daist. 



( Involucral bracts imbricated and searious at the edges 23 



(■ Receptacle flat or convex 9. Chetsanthemum. 



I Receptacle conical, much elongated as the fruit ripens 10. Mateicaey. 



22 



„„ ( Ray purple or blue 24 



''^ I Ray yellow , 25 



Involucral bracts and florets of the ray not numerous, oblong-linear . . 3. Aster. 



Involucral bracts and florets of the ray very numerous and narrow . 4. Eeigeeon. 



„, <• Involucral bracts linear, equal in length, or with a few very small outer ones . . 26 



1 Involucral bracts imbricated in two or more rows 28 



CRadieal leaves large, broadly heart-shaped or orbicular, distinct from the flowering 

 stem. Florets of the ray narrow and very numerous 2. Coltsfoot. 



24 { 



3C 



Radical leaves none, or at the base of the flowering stem. Florets of the ray 

 (. linear or oblong 37 



