292 CAEDUACEAE. 



13. S. arguta Ait. Stems 3-12 dm. tall, glabrous: blades of the lower cauline 

 leaves spatulate to oblong, elliptic, oval, or ovate, of the upper mainly elliptic 

 and more finely serrate than those of the lower leaves : inner bracts of the invo- 

 lucre linear-spatulate, 4.5-5 mm. long, the intermediate ones linear. — - Com- 

 mon, in woods and on banks. — Fall. 



14. S. juncea Ait. Stems 4-15 dm. tall, glabrous: blades of the lower cauline 

 leaves spatulate to oblong or elliptic and shallowly serrate, of the upper mainly 

 elliptic or sometimes linear-lanceolate, or nearly linear and finely serrate or 

 merely undulate : inner bracts of the involucre narowly linear, 4-5 mm. long. — 

 Common, in moist soil and open woods. — Sum. 



15. S. neglecta T. &. G. Stems 8-18 dm. tall, usually glabrous at least below: 

 blades of the lower cauline leaves spatulate, of the upper elliiitic or elliptic- 

 lanceolate, shallowly toothed, or merely undulate above: inner bracts of the 

 involucre linear, 4-4.5 mm. long, obtuse, ciliolate. — S. Eare, in swamps. 



— Schists. — Fall. 



16. S. serotina Ait. Stems 6-25 dm. tall, glabrous: blades of the lower cauline 

 leaves oblanceolate to narrowly oblong or elliptic, of the upper elliptic, oblong, 

 or oblong-lanceolate and serrate: inner bracts of the involucre narrowly 

 linear-lanceolate, about 3.5 mm. long. — Common, in moist places and thickets. 



— Fall. 



17. S. canadensis L. Stems 6-25 dm. tall, pubescent: blades of the lower 

 cauline leaves oblong or elliptic or broadened upward, of the upper oblong- 

 lanceolate to lanceolate and sharply serrate or nearly entire: inner bracts of 

 the involucre narrowly linear, 3-3.5 mm. long. — Common, in waste places and 

 thickets. — Fall. 



18. S. nemoralls Ait. Stems 1-9 dm. tall, pubescent: blades of the lower 

 cauline leaves mainly spatulate and ajapressed-serrate, of the upper oblanceo- 

 late to narrowly elliptic and less prominently toothed or entire : inner bracts of 

 the involucre narrowly linear, 3.5-4 mm. long. — Common, in fields and on 

 roadsides. — Fall. 



12. BOLTONIA L'Her. Perennial tall herbs. Leaves alternate: blades 

 entire, sessile or decurrent. Heads many, widely panicled. Involucres broadly 

 campanulate to hemispheric, many-flowered: bracts narrow or sometimes 



partly dilated. Eay-flowers often numerous: corollas with a short tube and 

 narrow ligules. Disk-corollas with a narrowly funnelform throat and short 

 tube: lobes triangular. Anthers as long as the filaments or longer. Achenes 

 flattened, broadest above the middle, the margins sometimes winged. Pappus a 

 ;series of short scales usually accompanied by 2-4 bristles. 



1. B. asteroi^es (L.) L'Her. Plants 1-2 m. tall: blades of the upper leaves 

 oblong to linear, 3-12 cm. long: outer bracts of the involucre linear-lanceo- 

 late, 2-3 mm. long, the inner slightly longer: ligules linear, white or pale, 

 5-6.5 mm. long: disk 6-12 mm. wide: corollas about 2 mm. long, the throat 

 about as long as the tube. — Susquehanna valley. Common, on low islands 

 and sandy or gravelly shores. — Sum. 



13. SERICOCARPUS Nees. Perennial low herbs. Leaves alternate : blades 

 entire or toothed. Heads in corymbs. Involucres campanulate to cylindric, 

 several-flowered: bracts broad, or the inner ones sometimes rather narrow. 

 Ray-flowers several: corollas with a long tube and a narrow, white or pink 

 ligule. Disk-corollas with a narrowly funnelform throat and a long tube: 

 lobes lanceolate. Anthers slightly longer than the filaments or shorter: ap- 



