1160 CARDUACEAE 
acuminate, sharply and rather finely serrate: heads rather crowded: involucres 6-7 mm. 
long, 4-5 mm. wide; bracts pubescent, sometimes hoary, acute or with short keel-like 
acuminations, the tips erect or slightly spreading : achenes pubescent : pappus purple. 
On plains or prairies, Missouri and Kansas, south to Texas. 
14. Vernonia Drummóndii Shuttlw. Foliage tomentose. Stems 1-2 m. tall, branch- 
ing above: leaves numerous; blades elliptic to elliptic-lanceolate or linear-elliptic, 1-3 
dm. long, acute or short-acuminate, sharply serrate: corymbs usually 1-4 dm. broad: 
peduncles barely enlarged upward: involucres rounded at the base, 8-12 mm. high; bracts 
ovate to oblong, acute or apiculate: achenes 4-5 mm. long, with smooth and glabrous ribs : 
pappus tinged with purple. 
On prairies, Illinois to Kansas, Alabama and Texas. 
15. Vernonia Guadalupénsis Heller. Foliage light green, minutely pubescent. 
Stems 3-15 dm. tall, corymbosely branched above, prominently ridged : leaves numerous ; 
blades linear or nearly so, 8-15 cm. long, 4-12 mm. wide, attenuate, undulate or remotely 
denticulate: involucres campanulate, 6-8 mm. high, 5-6 mm. broad; bracts abruptly 
pointed, hoary, with erect or slightly spreading tips: achenes 3.5-4 mm. long, prominently 
ribbed, slightly glandular: pappus purple. 
In limestone river bottoms, Texas. 
16. Vernonia fasciculàta Michx. Foliage glabrous, or pubescent above. Stems 
0.5-2 m. tall, simple below the inflorescence: leaves numerous ; blades linear to linear- 
lanceolate, 5-15 cm. long, attenuate, sharply serrate : corymbs 5-15 em. broad : peduncles 
slightly enlarged above: involucres campanulate at maturity, 5-6 mm. high, about 5 mm. 
broad ; bracts firm, oblong-ovate to nearly oval, acute or acutish, appressed: achenes 3 
mm. long, with smooth ribs : pappus purple. 
On plains and prairies, Ohio to South Dakota, south to Texas. 
17. Vernonia tenuifdlia Small. Foliage thinly pubescent. Stems 0.5-1 m. tall, 
branching above : leaves numerous ; blades linear or nearly so, 0.5-1.5 dm. long, acute, 
serrate, minutely punctate: corymbs 5-10 cm. broad, with rather few heads: peduncles 
slightly enlarged upward : involucres campanulate, 8-10 mm. high, purple; bracts ovate 
to oblong, erect, acute or mucronate: achenes about 4 mm. long, with smooth and gla- 
brous ribs: pappus straw-colored or tinged with purple. 
In dry soil, southern and western Texas. 
18. Vernonia marginàta (Torr.) Britton. Foliage pubescent above. Stems 1-1.5 
m. tall, corymbosely branched above ; leaves relatively few ; blades linear, 5-15 cm. long; 
or longer near the base of the stem, acute, entire: peduncles slightly enlarged above : in- 
volucres cylindric-campanulate, about 1 em. high; bracts ovate-lanceolate to oblong-lan- 
ceolate, acuminate, margined, with barely spreading tips: achenes 3-3.5 mm. long. 
In dry soil, Nebraska to Texas and New Mexico. 
19. Vernonia Lettermánii Engelm. Foliage glabrous or nearly so. Stems 0.5-1.5 
m. tall, fastigiately branched above: leaves numerous and crowded ; blades narrowly 
linear, 5-12 cm. long, acute, entire, each with a conspicuous midrib: peduncles angled, 
slightly enlarged upward : involucres cylindric or campanulate at maturity, 6-7 mm. high, 
narrowed at the base; bracts lanceolate to linear-oblong, acute or somewhat acuminate : 
achenes 4 mm. long, glandular, slightly rough on the ribs: pappus purplish. 
In sandy soil, Arkansas. 
20. Vernonia angustifdlia Michx. Foliage nearly glabrous. Stems 0.5-1 m. B 
often widely branched above: leaves numerous; blades linear, usually narrowly M 
cm. long, acute, revolute : peduncles variable, slightly enlarged near the top, 1-2 cm. ae 
or some heads sessile: involucres turbinate or turbinate-campanulate, 5-6 mm. e acu : 
or somewhat rounded at the base ; bracts lanceolate to oblong, acute or apiculate, with mor 
or less spreading tips: achenes 2 mm. long, with scabrous ribs : pappus purplish. 
In sand, Georgia and Florida to Mississippi. x 2 
21. Vernonia Texàna (A. Gray) Small. Foliage glabrate. Stems wand-ike, eio 
dm. tall, branching above: leaves relatively few ; blades oblong-oblanceolate to e 
lanceolate or linear, 5-20 cm. long, acute or acuminate, at least the lower ones Docs e 
toothed: corymbs with slender branches: peduncles variable, 0.5-5 cm. long, ey y 
enlarged above : involucres turbinate-campanulate, 5-6 mm. high ; bracts ovate to oblong, 
apiculate: achenes 3 mm. long, with sparingly barbed ribs: pappus pale purple. 
In sandy soil, Florida to Texas and ,Arkansas. S 
22. Vernonia Blodgéttii Small. Foliage glabrous below the inflorescence. erm 
often branched near the base, 2-5 dm. long, narrowly corymbose above: Tee = 
near the base of the stem ; blades oblong to linear, 2-4.5 cm. long, obtuse or acutish, 
