1158 



CARDUACEAE 



7. V. flaceidifolia. 



8. F. oligantha. 

 V. maxima. 



9. 



10. 

 11. 



12. 

 13. 

 14. 



V. gigantea. 

 V. ovalifolia. 



V. Baldmnii. 



V. interior, 



V. Drummondii. 



15. V. Guadalupensii. 



Outer bracts of the involucre merely acuminate. 4. V. glauca. 



Leaf-blades decidedly scabrous above. 



Leaf-blades coarsely toothed or crisped : bracts of the involucre with 



soft tips. 5. V. pulchella. 



Leaf-blades entire or minutely toothed : bracts of the involucre rigid. 6. V. scaberrima. 

 b. Bracts of the involucre obtuse to acuminate. 



Leaves with blades of various types, but not linear. 

 Leaf-blades glabrous or nearly so on both sides. 

 Involucres fully as broad as high. 

 Involucres much or manifestly higher than broad. 

 Bracts of the involucre obtuse or merely acute. 



Involucres hemispheric-campanulate, rounded at the base; 

 bracts appressed at maturity. 

 Involucres few-flowered, about 3 mm. high ; inner bracts 



narrowly oblong or linear-oblong. 

 Involucres many-flowered, 4 mm. to almost 5 mm. high ; inner 

 bracts broadly oblong. 

 Involucres cylindric, narrowed at the base; bracts loosely 

 spreading at maturity. 

 Bracts of the involucre, or some of them, acuminate. 

 Leaf-blades manifestly pubescent beneath, often densely so. 

 Involucres 4-6 mm. high. 



Bracts of the involucre with recurved tips. 

 Bracts of the involucre with erect or slightly spreading tips. 

 Involucres 8-12 mm. high. 

 Leaves with blades of a linear type. 



Stems, lower surfaces of leaf-blades and involucres glabrous or some- 

 what pubescent, but not white-woolly. 

 Leaf-blades smooth above. 



Lower surfaces of the leaf-blades, at least the midnerve, pubescent. 

 Lower surfaces of the leaf-blades glabrous. 



Leaves neither exceedingly numerous nor crowded. 

 Bracts of the involucres obtuse or merely acute. 



Involucres about 5 mm. broad. 16. V. fasciculata. 



Involucres about 8 mm. broad. 17. V. tenuifolia. 



Bracts of the involucres acuminate. 18. V. marginata. 



Leaves excedingly numerous and crowded. 19. V. Letternianii. 



Leaf-blades scabrous above. 



Bracts of the involucres with slender spreading tips. 



Bracts of the involucres with merely acute erect or appressed tips. 



Leaf-blades, at least the lower ones, remotely toothed. 21. 



Leaf-blades entire. 22. 



Stems, lower leaf-surfaces and involucres conspicuously white-woolly. 23. 



B. Leaves mainly or all basal. 24. 



1. Vemonia crlnita Raf. Foliage glabrous or somewhat pubescent, 

 tall, branched above : leaves numerous ; blades linear or linear-lanceolate, 

 attenuate at both ends, finely serrate : corymbs 1-2 dm. broad : peduncles club-shaped : in- 

 volucres hemispheric, becoming 1.5 cm. high and fully 1.5 cm. broad ; bracts greenish, 

 prolonged into filiform tips, the outer with little or no body : aclienes 5 mm. long, upwardly 

 barbed on the angles : pappus purplish. 



On plains and banks of streams, Missouri to Kansas and Texas. 



2. Vernonia Noveborac6nsi8 ( L. ) Willd. Foliage nearly glabrous, or pubescent. 

 Stems 1-3 m. tall, branching above : leaves rather numerous ; blades linear-lanceolate or 

 elliptic-lanceolate, 1-2 dm. long, acuminate, finely serrate or nearly entire, often minutely 

 pubescent beneath : corymbs 1-3 dm. broad, commonly irregular : peduncles angled, 

 slightly enlarged above : involucres hemispheric, about 5 mm. high ; bracts purple, ovate 

 or ovate-lanceolate, prolonged into filiform tips : achenes 4 mm. long, upwardly barbed 

 along the sharp angles : pappus purple. 



In thickets and open places, Massachusetts to Minnesota, Georgia and Missouri. 



3. Vernonia tomentosa (Walt.) Ell. Foliage rather thinly tomentose. Stems 1-2 

 m. tall, simple below : leaves rather numerous ; blades elliptic to narrowly elliptic-lanceo- 

 late, 1-2 dm. long, acute or acuminate, sharply serrate : corymbs 1-3 dm. broad : peduncles 

 slightly, if at all, enlarged above : involucres hemispheric, about 6 mm. high ; bracts 

 lanceolate to oblong-lanceolate, prolonged into subulate or filiform tips : achenes 3 mm. 

 long, sometimes nearly glabrous : pappUs straw-colored. 



On hillsides, New Jersey and Pennsylvania to North Carolina. 



4. Vernonia glatica (L. ) Britton. Foliage thinly tomentose. Stems 1-2 m. tall, 

 often widely branched above : leaves numerous ; blades linear-lanceolate to elliptic or 

 elliptic-oblanceolate, acute or short-acuminate, finely serrate : corymbs 1-3 dm. broad : 

 peduncles angled or winged, barely enlarged above : involucres hemispheric, about 5 mm. 

 high ; bracts lanceolate to nearly oblong, purple, the outer ones merely acuminate : achenes 

 2-3 mm. long, with the sharp ribs barbed : pappus straw-colored. 



On river banks, Virginia to Georgia. 



5. Vernonia pulchella Small. Foliage hirsute. Stems solitary or clustered, 3-10 

 dm. tall, branched above : leaves firm; blades oblong-lanceolate or oblong to nearly linear- 



20. V. angustifolia. 



V. Texana. 

 V. Blodgettii. 

 V. Lindheimeri. 

 V. oligophylla. 



Stems 1-4 m. 

 1-3 dm. long, 



