36 



ASTERACEAE 



y. Achenes of disk normal 

 (x) Achenes flat 

 (y) Achenes 4 angled 

 (b) Pappus present 

 x. Rays white 



(x) Pappus of bristles and awns 

 (y) Pappus a short-toothed crown 

 in. Receptacle nearly Hat 

 n. Receptacle conic or ovoid 

 y. Rays yellow or orange 



(x) Bracts united into a deep cup 

 m. Leaves finely cut; heads very small 

 n. Leaves coarsely cut ; heads large 

 (y) Bracts not united 

 m. Bracts squarrose-spreading 

 n. Bracts not squarrose-spreading 



(m) Leaves typically lobed ; achenes densely hairy 

 (n) Leaves not lobed; achenes smooth or nearly so 

 3. Flowers strap-shaped, all alike 



Achillea 

 Chrysanthemum 



Bolt on ia 



Chrysanthemum 



Matricaria 



Dysodia 

 Tagetes 



Grindelia 



Gaillardia 

 Helenium 



Ligulate head of dandelion, Taraxacum; showing the habit of the plant, long section of the head, 

 Jigulate or strap-shaped flower, and a parachute fruit. 



