242 COMPOSITE FAMILY 



Bracts of the involucre not enfolding the outer 

 akenes but merely standing next to them. 

 Disk-flowers intermingled with conspicuous 

 scales or bracts. 

 Rays yellow, disk purplish or black. 



Disk conical, 1 or 2 in. high 19. Rudbeckia, p. 255 



Disk flat 22. Helianthus, p. 256 



Rays and disk both yellow. 



Pappus present, of awns or scales (usu- 

 ally falling away from ripe akenes). . .21. Wyethia, p. 256 

 Pappus none or very obscure. 



Leaves broad; akenes 4-sided 20. Balsamorhiza, p. 255 



Leaves narrow; akenes flat 23. Helianthella, p. 257 



Disk-flowers without intervening scales or 

 bracts (i. e., receptacle naked). 



Pappus none; leaves all opposite 27. Whitneya, p. 259 



Pappus present; upper leaves alternate. 



Leaves very woolly, \ l / 2 in. or less long.. 28. Eriophyllum, p. 259 

 Leaves scarcely woolly, usually much 

 longer. 



Glandular; leaves toothed 31. Hulsea, p. 260 



Not glandular; leaves entire 32. Helenium, p. 260 



II. Discoid Compositae. 

 (Heads without rays.) 



A. Flower-heads yellow. 



Plant shrubby, the stems being decidedly woody. 



Pappus none 36. Artemisia, p. 261 



Pappus present, of numerous bristles. 



Leaves (roundish) and stems green, resinous. 6. Ericameria, p. 246 



Leaves white, very narrow; tall shrub 7. Chrysothamnus, p. 247 



Leaves green; stems white-woolly; low shrub. 



Haplopappus discoideus, p. 246 

 Plant not shrubby, the stems herbaceous. 



Pappus none 36. Artemisia, p. 261 



Pappus of 4 or 5 flat scales Chaenactis glabriuscula, p. 260 



Pappus of numerous slender bristles. 

 Bracts of the involucre unequal. 



Leaves broadly lanceolate 3. Chrysopsis, p. 245 



Leaves linear Erigeron inornatus, p. 251 



Bracts of the involucre equal. 



Pappus-bristles feathery 37. Raillardella, p. 263 



Pappus-bristles simple, not feathery. 



Leaves opposite, heart-shaped Arnica discoidea, p. 263 



Leaves alternate. 



Pappus soft and white 39. Senecio, p. 264 



Pappus rigid 13. Erigeron, p. 250 



B. Plower-heads not yellow. 



Plant not woolly in any part. 



Leaves merely toothed; perennials. 



Involucre not V\ in. high; akenes 5-angled.. 1. Eupatorium, p. 244 

 Involucre exceeding % in.; akenes 10-nerved. 2. Brickellia, p. 245 



Leaves finely lobed; annual 35. Matricaria, p. 261 



