GENERA OR FAMILIES. 365 



scarious at the margin ; receptacle conical, paleaceous ; 

 pappus a membrane. 



$$ Receptacle without scales ; (heads discoid). 



(27) Artemisia involucre ovate or round ; florets all tubular, 



those of the disk hermaphrodite, five-toothed, of the ray 

 slender, less numerous, entire, female ; receptacle naked or 

 hairy ; pappus none. 



(28) Tanacetum involucre hemispherical ; florets all tubular, those 



of the disk hermaphrodite,five-lobed,of the ray female, three- 

 lobed ; receptacle naked ; pappus membranous, entire. 



ft Pappus pilose. 

 % Anthers without bristles at the base. 



(29) Senecio involucre with bracteoles at the base, the scales 



scorched at the apex ; flowers flosculous or radiant ; recep- 

 tacle naked ; pappus soft, hairy. 



(30) Aster involucre imbricated, the scales linear, acute ; 



flowers radiant, of the ray female, in a single row, oblong ; 

 receptacle naked ; pappus hairy. 



(81) Chrysocoma involucre imbricated, hemispheri3al or ovate, 

 the scales linear ; florets all hermaphrodite, tubular ; recep- 

 tacle excavated ; pappus hairy, ciliated. 



J Anthers with two bristles at their base. 



(32) Inula involucre imbricated ; flowers radiant or tubular ; 



receptacle naked ; pappus hairy, simple. 



(33) Pulicaria involucre imbricated ; flowers radiant ; recep- 



tacle naked ; pappus double, the outer membranous. 



** Florets all tubular ; style swollen below its branches 

 (Cynarocephalese) . 



f Pappus pilose in many rows, equal, long, the hairs united 

 into a ring at the base. 



(34) Onopordum involucre imbricated, the scales pungent; 



