COMPOSITE FAMILY 251 



21. Tanacetum. — Florets all tubular; receptacle naked, broad; 

 fruit with a broad epigynous disk ; no pappus. 



22. Artemisia, — Florets few, all tubular; receptacle naked, 

 narrow ; fruit with a small epigynous disk ; no pappus. 



Tribe 6. Senecionidece. — Leaves scattered: ray-florets ligulate, or 

 absent : receptacle naked : anthers not tailed : pappus usually of very 

 soft hairs. 



23. TussiLAGO. — Leaves all radical ; heads solitary, many- 

 flowered ; outer florets ligulate. 



24. pETAsfTES. ^ Leaves all radical ; heads numerous, in a 

 raceme, many-flowered ; outer florets tubular. 



■^25. DoRONfcuM. — Involucral bracts in 2 or 3 rows, equal ; 

 ray-florets in i row, ligulate, without pappus ; florets all yellow ; 

 pappus of the disk-florets of several rows of stiff hairs, 



26. Sen^cio. — Involucral bracts in i row, equal ; florets all 

 yellow ; ray sometimes absent ; pappus of several rows of soft, 

 slender hairs. 



Tribe']. Cynaroidece. — Leaves scattered, usually spinous: bracts 

 imbricate, spinous : florets all tubular and usually perfect : receptacle 

 scaly ; pappus generally present. 



27. Carl/na. — Outer bracts spinous ; inner chaffy and spreading ; 

 anthers tailed ; pappus in i row, branched and feathery. 



28. Arctium. — Involucre globose ; outer bracts hooked ; anthers 

 tailed ; pappus in several rows of short simple hairs. 



29. Carduus, — Leaves decurrent ; bracts spinous ; anthers 

 scarcely tailed ; fruit compressed ; pappus in many rows of long, 

 equal, rough hairs, 



30. Onopordum. — Differing from Carduus mainly in its 

 honeycombed receptacle and 4-angled fruit. 



31. SiLYBUM, — Resembling Carduus, but with united filaments 

 and silky pappus. 



32. Saussurea, — Bracts not spinous ; anthers tailed ; pappus m 

 2 rows, outer brisdy, inner longer, feathery, 



33. Serratula, — Bracts not spinous ; anthers not tailed ; 

 pappus in several rows of long unequal hairs, the inner 

 longest. 



34. Centaurea. — Outer florets usually large, unsymmetrical 

 and neuter ; pappus in several rows of short unequal hairs, the 

 second row longest, or rarely absent. 



