COMPOSITAE (composite FAMILY) 481 



++ Pappus double. ' 



8. Chiysopsis. Heads many-flowered; rays numerous. The outer pappusof very sniall 



chaSy bristles, much shorter than the inner of copious capillary bristles. 

 ++ ++ Pappus simple. ' 



It. Pappus a single row of capillary bristles. 



9. Chrysothamnus. Involucre narrowly turbihate; the bracts chartaceous, usually in 



5 vertical ranks. Rays none. Pappus a single row of capillary bristles. 



10. Isocoma. Involucre broadly turbinate; the bracts imbricated but not in vertical 



ranks. Rays none. Pappus as in the preceding. 



aa. Pappus of many unequal bristles. 



11. Sideranthus. Involucre hemispherical; the bracts chartaceous, with green tips. 



Rays usually present. Leaves with spinulose-tipped teeth. 



12. Pyrrocoma. Inyolucre hemispherical; the bracts more or less foliaceous. Rays 



conspicuous. Leaves with spinulose-tipped teeth, the basal large, the cauline 

 reduced. ^ 



13. Oonop^is. Involucre from hemispherical to turbinate; the bracts more or less green- 



tipped and cuspidstte-acuminate. Stems leafy up to the sessile heads. 



14. Macronema. Involucre turbinate; the outer bracts foliaceous. Rays often wanting. 



Stems leafy throughout. 



15. Stenotus. Involucre hemispherical; the bracts not green-tipped, mucronately acute. 



Rays few-several. Stems scapose or at least naked above. 



16. Tonestus. Involucre broadly hemispherical; the bracts herbaceous, very obtuse. 



Rays conspicuous. Stems low, equably leafy. 



17. Petradoria. Involucre turbinate to ovoid; the bracts in more or less distinct vertical 



rows. Achenes cylindric, 10-striate. 

 IS. Oreochrysum. Involucre campanulate; the bracts chartaceous or the outer foliaceous. 

 Rays 12-20. Achenes angled.^ 



aaa. Pappus of numerous capillary bristles. 



19. Solidago. Heads few-mahy-fiowered, numerous, in racemes, panicles, or corymbs; 



rays 1-16. 

 ** Ray-flowers white, blue, pink, or purple, rarely yellow in no. 27. . 

 ■(- Pappus very short, a mere crown or a lew scales or awn-like bristles. 



20. Townsendia. Involucre broad, many-flowered; the bracts more or less scarious^ 



margined. 



•4- +■ Pappus of numerous, long, and capillary bristles. 

 ++ Rays conspicuous. 



21. Xylorhiza. Involucral bracts in about 2 series, mucronulate, carinate below, her- 



baceous with scarious margins. 

 . 22. Aster. Involucral bracts in several series, usually herbaceous at tip, not reflexed or 

 recurved. 



23. Machaeranthera. Involucral bracts herbaceous and spreading, or recurved or re- 



flexed, in several series. 



24. Oreastrum. Involucre hemispherical; the bracts narrow and aubequal. Stems scapi- 

 t form, monocephalous. 



25. lonactfe. Involucre hemispherical; the bracts imbricated, coriaceous, and wholly 



appressed. Stems equably leafy. 



26. Leucelene. Involucre turbinate; the bracts narrow, herbaceous but scarious-mar- 



gined. Leaves narrow, subulate, niunerous, and mostly appressed. 



27. Erigeron. Heads many-flowered, on naked peduncles. Involucres of narrow equal 



bracts in two rows. Pappus simple or with some outer minute scales. 



28. Wyomingia. Heads large; the involucral bracts in 3-4 series, rigid with a thickened 



midrib. Pappiis in 2 series, the outer short, multisquamellate. 

 ++ ++ Rays inconspicuous or none. 



29. Leptilon. Heads small, radiate or discoid; involucres campanulate; bracts narrow, 



in 2-3 series. Annuals. 

 ' 30. Baccharis. Heads rayless, many-flowered, dioecious (all pistillate or all staminate). 

 ' Smooth glutinous shrubs. 

 Tribe IV. INULEAE. Heads discoid (radiate only in Inula), the pistillate flowers mostly 

 filiform and truncate. Anthers sagittate, the basal lobes attenuate into tails. Style- 

 branches with unappendaged, obtuse or truncate naked tips. Pappus capillary or 

 none. 



* Receptacle chaffy. 



31. Filago. Receptacle hemispherical or conical; fertile flowers in 2 sets separated from 



each other by a ring of chaffy bracts. Low woolly annuals. 

 * * Receptacle naked; involucral bracts many, scarious; floccose-woolly herbs. 

 • -t- Heads dioecious or nearly so. 



32. Antennaria. Heads dioecious. Pappus of sterile flowers club-shaped or barbellate; 



of the fertile capillary, united at base and deciduous together. 



33. Anaphalis. Heads dioecious or nearly so. Pappus not thickened above or at all 



united at base. 



t- *- Heads all fertile throughout. 



34. Nacrea. Flowers all hermaphrodite; pappus olavate-thickened upward. 



35. Gnaphalium. Flowers all fertile but only the inner hermaphrodite; pappus fcap- 



illary. 

 Tribe V. HELIANTHEAE. Heads radiate or discoid; involucre not scarious (nut-like 

 in fruit in nos. 42, 43 and 44). Receptacle chaffy. Pappus never capillary, sometimes 

 none. Anthers not caudate. Style-branches truncate or hairy-appendaged. 

 * Ray-flowers fertile and ligulate (sometimes obscurely so): disk-flowers sterile. 

 +- Rav flowers with conspicuous ligules. 



36. Melampodium. Involucral bracts in 2 very dissimilar sets. 



