CAKDUACEAE. 291 



2. S. flexicaulis L. Similar to S. caesia in habit: blades of the cauline 

 leaves elliptic, sometimes narrowly so, 2.5-3 cm. long, sharply serrate, pubes- 

 cent about the veins beneath, except sometimes in age: inner bracts of the 

 involucre linear-oblong, 4-4.5 mm. long. Common, on the river hills and along 

 creeks. Fall. 



3. S. squarrosa L. Stems 4-15 dm. tall, usually somewhat pubescent above: 

 blades of the lower cauline leaves oval to ovate, coarsely toothed and 1-2 dm. 

 long, of the upper smaller and shallowly toothed or undulate: inner bracts of 

 the involucre oblong : disk-corollas with lanceolate lobes. Frequent, in woods 

 along the Octoraro Creek. Schists. Sum. 



4. S. tricolor L. Stems 2-12 dm. tall, pale-hirsute: blades of the lower cauline 

 leaves obovate, oval, elliptic or spatulate, shallowly crenate-serrate and 1-2 dm. 

 long, of the upper smaller and elliptic, oblong, or oblanceolate : inner bracts of 

 the involucre oblong, 3.5-4 mm. long, obtuse: disk-corollas 3.5-4 mm. long. 

 Common, in woods and thickets -Late sum. 



5. S. hispida Muhl. Similar to S. 'bicolor in habit, the stems often densely 

 hirsute: inner bracts of the involucre broadly linear, 4-4.5 mm. long: disk- 

 corollas 4.5-5 mm. long. N. Frequent, on dry hillsides. Sandstones and 

 shales. Late sum. 



6. S. speciosa Nutt. Stems 7-19 dm. tall, glabrous, at least below: blades of 

 the lower cauline leaves elliptic to oval and 1-2 dm. long, of the upper smaller 

 and mainly elliptic to elliptic-lanceolate, all shallowly toothed: inner bracts of 

 the involucre linear-spatulate, 5-6 mm. long: disk-corollas 3.5-4 mm. long. N. 

 Occasional, on hillsides. Sandstones and shales. Fall. 



7. S. racemosa Greene. Stems tufted, 1-4.5 dm. tall, glabrous: blades of the 

 cauline leaves spatulate to linear, 2-8.5 cm. long or smaller above, acute or 

 acuminate, shallowly serrate or entire: inner bracts of the involucre linear- 

 cuneate to nearly linear, 4-5 mm. long, acute or acutish: achenes pubescent. 

 Lower Susquehanna valley. Occasional, on rocky islands. Schists. Fall. 



8. S. puberula Nutt. Stems 3-9 dm. tall, puberulent: blades of the lower 

 cauline leaves spatulate to oblanceolate and appressed-serrate or crenate- 

 serrate, of the upper oblanceolate to elliptic or linear-elliptic: inner bracts of 

 the involucre linear-lanceolate, 3.5-4 mm. long, acute: achenes glabrous. 

 N. S. Not very common, in dry places. Sandstones and shales, schists. 

 Fall. 



9. S. patula Muhl. Stems 6-15 dm. tall, glabrous : blades of the lower cauline 

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

 oblanceolate or elliptic, all scabrous above: inner bracts of the involucre linear, 

 4.5-5 mm. long : disk-corollas about 4 mm. long. Frequent, in moist grounds 

 and meadows. Fall. 



10. S. odora Ait. Stems 5-13 dm. tall, minutely pubescent: blades of the 

 lower cauline leaves linear-spatulate to linear-oblong, of the upper lanceolate 

 to linear-lanceolate or linear, all entire: inner bracts of the involucre narrowly 

 linear-lanceolate, glabrous, 4-5 mm. long. Lower Susquehanna valley. Com- 

 mon, in thickets. Schists. Late sum. 



11. S. rugosa Mill. Stems 3-22 dm. tall, pubescent : blades of the lower cauline 

 leaves spatulate to oblong or elliptic, of the upper elliptic, lanceolate, or 

 oblong-ovate, all sharply toothed : inner bracts of the involucre linear or oblong- 

 linear, 4.5-5 mm. long, the intermediate ones lanceolate. Common, on dry 

 banks and in thickets. Fall. 



12. S. ulmifolia Muhl. Stems 5-12 dm. tall, glabrous: blades of the lower 

 cauline leaves spatulate, elliptic or oblong, of the upper elliptic-lanceolate or 

 oblong-lanceolate, all serrate: inner bracts of the involucre linear, 4-4.5 mm. 

 long, or rarely shorter. Common, in thickets and open woods. Fall. 



