290 



CAKDUACEAE. 



1. E. graminifolia (L.) Nutt. Plants 13-14 dm. tall: leaf -blades linear, 

 mainly over 4 mm. wide: heads in dense clusters: involucres campanulate, the 

 inner bracts 3.5-4 mm. long: achenes pubescent. Common, in fields and 

 thickets. Late sum. 



11. SOLIDAGO L. Perennial caulescent herbs. Leaves alternate: blades 

 various, mostly toothed. Heads relatively small, paniculate or thyrsoid. Invo- 

 lucres campanulate, turbinate, or cylindric, few-several-flowered. Bracts vari- 

 ous, the inner narrow, at least relatively so, and much longer than the outer. 

 Bay-flowers few: corollas with a slender tube and a yellow or rarely white 

 ligule. Disk-corollas with a funnelform or campanulate throat and a tube 

 nearly or quite as long: lobes lanceolate. Anthers nearly or quite as long as 

 the filaments. Stigmas mostly lanceolate. Pappus of 1 or 2 series of rough 

 capillary bristles. GOLDENROD. 



Heads in axillary short or raceme-like clusters subtended by leaf-like bracts. 



Stem and branches terete : stem-leaves with relatively narrow, shallowly toothed, 



blades. 

 Stem and branches angled : stem-leaves with relatively broad, 



deeply toothed, blades. 



Heads in a terminal inconspicuously bracted panicle or thyrsus. 

 Tips of the involucral bracts, at least some of them, spread- 

 ing or recurved. 

 Tips of the involucral bracts erect or appressed. 



Inflorescence nearly equilateral, the branches erect or as- 

 cending : heads not secund on the branches. 

 Bracts of the involucre decidedly obtuse. 

 Achenes glabrous. 



Stems copiously pubescent. 



Achenes columnar : ray-flowers with white 



ligules. 

 Achenes dilated upward : ray-flowers with 



yellow ligules. 



Stems glabrous or merely puberulent. 

 Achenes pubescent. 



Bracts of the involucre acute or acutish. 

 Inflorescence 1-sided, the branches spreading or recurved : 



heads secund. 

 Leaf-blades pinnately veined, not 3-ribbed. 



Internodes of the stem prominently angled below 



the leaves. 



Internodes of the stem terete or essentially so. 



Stem manifestly pubescent, rarely only in lines. 



Ray-flowers 3 or 4 : leaves glabrous ; blades 



entire, narrow. 

 Ray-flowers 6-9 : leaves pubescent ; blades 



toothed, broad. 



Stem glabrous, at least below the inflorescence. 

 Branches of the inflorescence pubescent. 

 Ray-flowers mostly 6-8 : involucre cylin- 

 dric, few-flowered : achenes pubescent. 

 Ray-flowers mostly 3-5 : involucre cam- 

 panulate,. many-flowered : achenes 

 glabrous. 



Branches of the inflorescence glabrous. 

 Involucre less than 5 mm. high. 

 Involucre over 5 mm. high. 

 Leaf-blades manifestly 3-ribbed. 

 Stem glabrous. 

 Stem pubescent. 



Cauline leaves with relatively long blades, 



acuminate or attenuate. 



Cauline leaves with relatively short blades, ob- 

 tuse or merely acute. 



1. 8. caesia. 



2. 8. flexicaulis. 



3. 8. squarrosa. 



4. S. Ucolor. 



5. 8. hispida. 



6. 8. speciosa. 



7. 8. racemosa. 



8. 8. puberula. 



9. 8. patula. 



10. 8. odora. 



11. 8. rugosa. 



12. 8. ulmifolia. 



13. 8. arguta. 



14. 8. juncea. 



15. 8. neglecta. 



16. 8. serotina. 



17. 8. canadensis. 



18. 8. nemoralis. 



1. S. caesia L. Stems 3-11 dm. tall, glabrous: blades of the upper cauline 

 leaves spatulate to broadly linear or linear-lanceolate, 6-14 cm. long, serrate, 

 glabrous: inner bracts of the involucre linear-lanceolate, 3-3.5 mm. long. 

 Common, in woods and on banks. Fall. 



