2 9 o ASTER FAMILY 







PTILORIA Rafinesque 1832 



(Gr. ptilon, feather) 

 ( Stephanomeria Nuttall) 



Heads with pink perfect strap-flowers, achenes oblong to linear, 5- 

 ribbed, sometimes beaked, pappus of hair-like bristles ; receptacle flat, with- 

 out chaff, involucre cylindric to oblong, main bracts in 1 row with a few 

 shorter ones ; heads solitary or panicled ; leaves alternate or basal, entire to 

 pinnatifid, those of the stem often mere scales; annual, biennial or peren- 

 nial. 



1. Perennial P.tenuifolia 



2. Annual or biennial 



a. Bristles of the pappus plumy to the base; in- 



volucre 4-8-flowered P. virgdta 



b. Bristles of the pappus not plumy below the 



middle ; involucre 5-flowered P. e.rigna 



RATIBIDA Rafinesque 1818 CONE FLOWER 



(Of unknown origin and meaning) 



PL 39, fig. 1, 6. 



Heads with yellow to purple-brown neutral ray-flowers, disk-flowers 

 yellow, perfect, achenes oblong, flattened, margined or winged, pappus of 

 1-2 teeth, often with small intermediate scales ; receptacle oblong to 

 cylindric, with chaff, scales of the involucre in 2-3 rows ; heads solitary on 

 the ends of the branches ; leaves alternate, pinnately divided ; perennial. 



1. Rays 2-4 cm. long, yellow or more or less purple- 



brown; disk cylindric 1-2 in. long R. columndris 



2. Rays 5-9 mm. long, usually brown-purple; disk 



oblong, 1 cm. long R. tagetes 



RUDBECKIA Linne 1753 BLACKEYED SUSAN, GOLDEN GLOW 

 (Named for Rudbeck, a Swedish botanist) 



PI. 39, fig. 2, 4. 



Heads with yellow to orange-yellow neutral ray-flowers, or none, disk- 

 flowers purple or yellow, perfect, achenes oblong, 4-angled, pappus crown- 

 like or of 2-4 short teeth or none; receptacle convex to conic, with chaff, 

 involucre hemispheric, the bracts imbricated in 2-4 rows ; heads solitary ; 

 leaves alternate, entire to pinnatifid; perennial to biennial. 

 1. Rays present 



a. Leaves entire or toothed; stems 1-3 ft. high, 



rough-hairy R, hirta 



