GENERA AND SPECIES. 
Involucre hemispheric; heads solitary on leafless 
stalks. 
Achenes glabrous, flat; ray yellow; leaves 
narrow-linear, short. Dwarf erect annual; 
pappus-bristles 8 to 12, yellow at the tips... 
Achenes silky; leaves stalked, oblong or lan- 
ceolate ; scabrous-pubescent somewhat viscid 
annual AP , 
Achenes silky; heads ame HE 
ray white; pappus-bristles 7 to 10 . 
Involucresomewhat turbinate or cylindrical, pone 
silky; leaves narrow-linear or filiform; heads 
sessile in dense corymbs. 
Ray yellow or white; bristles 15 to 20 ba 
Ray white, bristles numerous 
Stems or foliage or both woolly or cottony ee 
leaves linear. 
Achenes silky; heads in cor ymbs; ray white 
Achenes glabrous, smooth or papillary. 
Inner phyllaries attenuated into stalks, heads 
solitary on long leafless stalks. 
Outer phyllaries subulate; ray yellow; 
leaves stem-clasping ee se 
Outer phyllaries broad; ray Sits or 
pinkish; leaves crowded at the base 
Inner phyllaries with broad claws. 
Achenes rough; heads solitary ; ray white 
or yellow , 
Achenes smooth; headend in coryeibie quads 
decurrent F : Be Ae 
1. Inner phyllaries without ray-like tips. 
Stems and foliage glabrous. a brown; achene 
glabrous .. es 
Stems and rateee eeatity pais, or ee Aapreae 
Phyllaries rigid; achene rough; pappus of marginal 
flowers wanting, of the others of 1 to 4 flat 
ciliate bristles. Dwarf 
Phyllaries membranous ; achene smooth ; ‘pappus: 
bristles 10, plumose. Minute 
Stems or foliage or both, woolly or cottony evade 
Heads small, usually i in dense terminal corymbose 
clusters. 
Achenes almost glabrous ; flowers in each head 2 
to5.. 
Achenes papillary ; ; flowers 15 to. 20 ; ‘Pappus 
bristles 8 to 5 os 
hyalospermum 
heteranthum 
floribundum 
tenellum 
pygmaeum 
corymbifiorum 
stipitatum 
incanum 
Cotula 
Haigii 
laeve 
dimorpholepis 
exiguum 
moschatum 
pterochaetum 
