CARDUACEAE 1167 



blades linear, 2-6 cm. long, acute, sometimes undulate : heads numerous, sometimes very 

 numerous : involucres 5-6 mm. high ; bracts oblong to linear or linear-lanceolate, canes- 

 cent and glandular, obtuse or apiculate : corollas white : achenes 2.5-3 mm. long. 

 In sandy soil, Massachusetts to Florida and Mississippi. 



15. Eupatorium Torreyanum Short. Finely pubescent. Stems 4-8 dm. tall, corym- 

 bose above : leaves mainly opposite, spreading or ascending, small ones clustered in the 

 axils of the larger ; blades broadly linear to oblong-lanceolate, coarsely serrate or laciniate, 

 prominently nerved beneath : involucres 4.5-6 mm. high ; bracts oblong or oyate-oblong to 

 linear, scarious-margined, obtuse : corollas white : achenes 3 mm. long, sparingly glandu- 

 lar. [E. hyssopifolium var. laciniatum A. Gray. ] 



In sandy soil, Pennsylvania and Kentucky, Florida and Tennessee. 



16. Eupatorium recurvans Small. Similar to E. Tovreyanum in habit, but usually 

 smaller. Stem often slender : leaves recurved or reflexed ; blades narrowly oblong to 

 lanceolate, 1.5-4 cm. long, coarsely toothed : involucres 3-3.5 mm. high : achenes about 2 

 mm. long. 



In pine lands, Georgia and Alabama to Florida. 



17. Eupatorium andmalum Nash. Tomentulose. Stems 8-15 dm. tall, branching 

 above : leaves opposite, small ones clustered in the axils of the larger ; blades ovate-lance- 

 olate to ovate, 3-7 cm. long, acute, rather coarsely and sharply serrate : involucres narrow, 

 5-6 mm. high, 5-flowered ; bracts linear-lanceolate to linear, pubescent and somewhat 

 glandular, acute or acutish, scarious-margined : corollas white : achenes 2.5 mm. long, 

 glandular. 



In sandy soil, Florida. 



18. Eupatorium lancifolium (T. & G. ) Small. Similar to E. semiserratum in habit, 

 but more slender, the stem from the base to the inflorescence, or near it, and leaves glabrous : 

 leaves spreading ; blades linear-oblong, 2-5 cm. long, acute or acutish, shallowly but 

 markedly toothed at least above the middle, prominently 3-ribbed from near the base : in- 

 volucres about 3 mm. high : achenes 2-2.5 mm. long. [E, parviflorum var. lancifolium 

 T. & G.] 



In dry soil, Louisiana and Texas. 



19. Eupatorium semiserratum DC. Tomentulose. Stems 5-12 dm. tall, branched 

 pbove : leaves rather numerous ; blades oblong to elliptic, sometimes narrowly so, 3-10 cm. 

 long, acute, sharply serrate, especially above the middle, prominently nerved beneath : 

 heads numerous : involucres 3-4 mm. high ; bracts oblong-ovate to linear, obtuse, canes- 

 cent : corollas white or pinkish : achenes about 2 mm. long, minutely glandular. 



In sandy soil, Virginia to Missouri, south to Florida and Texas. 



20. Eupatorium altissimum L. Hoary-tomentulose. Stems 8-20 dm. tall, branch- 

 ing above : leaves numerous ; blades linear-lanceolate, to linear-elliptic, often very nar- 

 rowly so, acuminate at both ends, sharply serrate above the middle or the upper ones 

 entire, conspicuously 3-nerved : heads very numerous, usually crowded : involucres 5-6 

 mm. high ; bracts oblong, canescent, obtuse, scarious-margined : corollas white : achenes 

 3.5 mm. long, minutely glandular. 



In dry soil, Iowa to Pennsylvania, North Carolina and Texas. 



21. Eupatorium tortifolium Chapm. Tomentulose above. Stems 3-7 dm. tall, 

 branched above : leaves numerous, opposite and alternate ; blades spatulate, oblanceolate 

 or nearly linear, 1-3 cm. long, obtuse or acutish, vertical, the lower ones often reflexed : 

 heads often crowded : involucres 4-5 mm. high ; bracts linear-oblong to linear, obtuse or 

 acute, hairy : corollas white : achenes 2.5 mm. long, glandular. 



In sand, South Carolina to Florida and Alabama. 



22. Eupatorium cuneifolium Willd. Tomentulose above. Stems 4-8 dm. tall, 

 branching above : leaves rather numerous ; blades cuneate, oblong-cuneate or linear-ob- 

 long, 1-3 cm. long, obtuse, serrate beyond the middle, or the upper ones entire : heads 

 numerous : involucres 5-7 mm. high ; bracts lanceolate to linear-oblong or linear, obtuse 

 or acutish, with scarious margins and apex : corollas white : achenes nearly 3 mm. long, 

 glandular. 



In sand, South Carolina to Florida and Alabama. Summer and fall. 



23. Eupatorium leuc<51epis T. & G. Rough pubescent or tomentulose above. 

 Stems 3-8 dm. tall, corymbosely branched above : leaves mainly opposite ; blades linear to 

 lanceolate, 3-7 cm. long, acute, remotely serrate or nearly entire, 1 -ribbed, scabrous : 

 heads mostly few : involucres 6-7 mm. high ; bracts lanceolate to linear, acuminate, canes- 

 cent, the inner with scarious tips : corollas white : achenes 2.5 mm. long, glandular. 



In low pine lands, New York to Florida and Louisiana. Summer and fall. 



