194 coMPOSiT.E. (composite family.) 



sessile, 3-nervcd, sparingly seiTate ; corvTnbs dense; heads 15-20-flowered ; 

 scales of the involucre very obtuse, strongly striate. — Near Natchez, Mississippi, 

 and South Florida. July - November. — Flowers blue. 



* * Scales (if the involucre purplish, scarious, obtuse, imbricated in several rows, the 



outer ones mttch shorter: leaves whorled: Jiowers purplish. 



2. E. purpureum, L. Smooth or pubescent; stem simple, tail, often 

 spotted or dotted ; leaves petioled, 3-6 in a whorl, varying from lanceolate to 

 ovate, coarsely serrate, roughish ; corymbs large, compound ; heads 5 - 10-flow- 

 ered. — Swamps, rarely in dry woods, Florida to Mississippi, and northward. 

 Aug. -Sept. — Stem 3° -10° high, solid or hollow, even or grooved. A vari- 

 able species, including E. ternifolium, E. maculatum, and E. verticillatum, 

 Ell. 



* * * Scales of the involucre (green or white) imbricated in 2-3 rows, the outer ones 

 shorter: heads 5 - 20-Jlowered : leaves, achenia, i^-c. dotted icitk resinous (/lands: 

 Jiowers white. 



*- Heads b-flowtred: leaves undivided, sessile or narrowed into a stalk-like base 

 {except No. 13.) 



3. E. hyssopifolium, L. Pubescent ; leaves opposite, the upper ones 

 alternate, lanceolate or ovate-lanceolate, coarsely serrate or toothed, 3-ribbed at 

 the base ; scales of the involucre lanceolate, obtuse, mucronate, shorter than the 

 flowers. (E. linearifolium, Walt.) — Varies with the leaves narrow-linear and 

 entire, the lower ones 4 in a Avhorl, and numerous smaller ones in the axils. — 

 Low ground, Florida to Mississippi, and nortiiward. Sept. — Stem 2° - 3° 

 high. Leaves rigid, sometimes all alternate. 



4. E. cuneifolium, Willd. Pubescent; leaves short, obovate-oblong, 

 sparingly serrate near tlie summit, or entire, 3-ribbed, mostly very obtuse ; scales 

 of the involucre obtuse, shorter than the flowers. (E. glaucesccns, Ell.) — Rich 

 shaded soil, Florida to South Carolina. Sept. — Stem 2° -3° high. Leaves 1' 

 long, pale and somewhat glaucous on botli sides. 



5. E. leucolepis, Torr. & Gray. Stem simple, virgate, minutely pubes- 

 cent and roughened ; leaves somewhat remote, lanceolate or linear-lanceolate, 

 acute, serrate, very rough on both sides, obscurely 3-ribbed ; corymbs ample^ 

 hoary ; scales of the involucre lanceolate, acuminate, white and scarious at the 

 apex, as long as the flowers. — Flat pine baiTcns, Florida and northward. Sept. 

 — Stem 2° high. Leaves l'-2' long. 



6. E. parviflorum, Ell. Tomentose ; stem slender, simple or branched 

 above ; leaves alternate, opposite, or whorled, lanceolate, acute, strongly serrate, 

 3-ribbed near the base, tapering into a petiole ; corymbs large ; scales of the in- 

 volucre lanceolate, obtuse, shorter than the flowers, scarcely longer than the 

 mature achenia. — Margins of ponds and wet places, Florida to North Carolina, 

 and westward. Sept. — Stem 2° high. Leaves 2' long, strongly veined. Flow- 

 ers smallest of all. 



7. E. seabridum, Ell. ? Stem stout, tomentose ; leaves opposite, ovate- 

 lanceolate, acute at both ends, thickly and unequally serrate, rough above, tomen- 

 tose and somewhat glaucous beneath, 3-ribbed from near the base ; corymbs 



