1158 CARDUACEAE 
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. 7. V. flaccidifolia.: 
Involueres much or, manifestly higher than broad. 
Braets of the involucre obtuse or merely acute. 
Involucres hemispheric-campanulate, rounded at the base; 
braets appressed at maturity. 
Involucres few-flowered. about 3 mm. high; inner bracts 
narrowly obiong or linear-oblong. 8. V. oligantha. 
Involueres many-flowered, 4 mm. to almost 5 mm. high ; inner 
bracts broadly oblong. : 9. V. maxima. 
Involueres cylindric, narrowed at the base; bracts loosely 
spreading at maturity. 10. V. gigantea. 
Braets of the involucre, or some of them, acuminate. 11. V. ovalifolia. 
Leaf-blades manifestly pubescent beneath, often densely so. 
Involucres 4-6 mm. high. 
Bracts of the involucre with recurved tips. 12. V. Baldwinii. 
Bracts of the involucre with erect or slightly spreading tips. 13. V. interior, — 
Involucres 8-12 mm. high. 14. V. Drummondii. 
Leaves with blades of a linear "e. 
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. 15. V. Guadalupensis. 
Lower surfaces of the leaf-blades glabrous. 
Leaves neither exceedingly numerous nor crowded. 
Bracts of the involucres obtuse or merely acute. 
Involueres about 5 mm. broad. 16. V. fasciculata. 
Involucres about 8 mm. broad. 17. V. tenuifolia. 
Bracts of the involueres acuminate. 18. V. marginata. 
Leaves excedingly numerous and crowded. 19. V. Lettermanii. 
Leaf-blades scabrous above. ER 
Bracts of the involucres with slender spreading tips. i 20. V. angustifolia. 
Braets of the involucres with merely acute erect or appressed tips. 
Leaf-blades, at least the lower ones, remotely toothed. 21. V. Tezana. — 
Leaf-blades entire. 22. V. Blodgettii. | 
Stems, lower leaf-surfaces and involucres conspicuously white-woolly. 23. V. Lindheimert. 
B. Leaves mainly or all basal. 24. V. oligophylla. 
1. Vernonia crinita Raf. Foliage glabrous or somewhat pubescent. Stems 1-4 m. 
tall, branched above: leaves numerous; blades linear or linear-lanceolate, 1-3 dm. long, 
attenuate at both ends, finely serrate: corymbs 1-2 dm. broad: peduncles club-shaped : in- 
volucres hemispherie, becoming 1.5 cm. high and fully 1.5 cm. broad; bracts greenish, 
prolonged into filiform tips, the outer with little or no body: achenes 5 mm. long, upwardly 
barbed on the angles: pappus purplish. 
On plains and banks of streams, Missouri to Kansas and Texas. 
2. Vernonia Noveboracénsis (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, pee 
or ovate-lanceolate, prolonged into filiform tips: achenes 4 mm. long, upwardly bar 
along the sharp angles: pappus purple. 
In thickets and open places, Massachusetts to Minnesota, Georgia and Missouri. : 2 
3. Vernonia tomentósa ( Walt.) Ell. Foliage rather thinly tomentose. | Stems es 
m. tall, simple below : leaves rather numerous ; blades elliptic to narrowly elliptic- tance 
late, 1-2 dm. long, acute or acuminate, sharply serrate : corymbs 1-3 dm. broad : e "e 
imd if at all, enlarged above: involucres hemispheric, about 6 mm. high; brac 
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. 1l 
4. Vernonia glaùca (L.) Britton. Foliage thinly tomentose. Stems 1-2 m. ta's 
often widely branched above: leaves numerous ; blades linear-lanceolate to elliptic x 
elliptic-oblanceolate, acute or short-acuminate, finely serrate : corymbs 1-3 dm. ce 
peida angled or winged, barely enlarged above : involucres hemispheric, about Aim 
igh ; bracts lanceolate to nearly oblong, purple, the outer ones merely acuminate : ache 
2-3 mm. long, with the sharp ribs barbed : pappus straw-colored. 
On river banks, Virginia to Georgia. d. 3-10 
5. Vernonia pulchélla Small. Foliage hirsute. Stems solitary or acciri fuii 
dm. tall, branched above: leavesfirm ; blades oblong-lanceolate or oblong to neariy 
