Obdeb 70.— composite. 427 



ecales in B or 6 series, closely imbricated ; rays longer Hum ifte invol ; ach. glab- 

 rous. — Swamps, Fla. (Chapman.) A curious Aster, very slender, with large hds., 

 20 to 30-rayed, spreadiog 2', purple. 



47 A. linifolius L. Sea Aster. St. paniculate, much branched from the base ; 

 Ivs. long, linear, very acute, the uppermost subulate ; invol. cylindric, with subu- 

 late .scales in about 3 rows ; rays minute, in two series, scarcely exserted. — An 

 annual species, found in salt marshes, Mass. to Car. St. 12 to 18' high, very- 

 smooth, thick, reddish. Lvs. smooth, sessile. The plant i,s very branching, with 

 numerous small hds., almost discoid' from the shortnes-s of the rays. Aug. 



48 A. subulatus Mx. Annual ; slender, much branched, glabrous ; branches 

 eorymbed, slender ; lvs. linear-subtilate, scabrous, long-linear below ; scales lanco- 

 linear, acute, in 2 or 3 series ; rays numerous, narrow, longer than the disk, in one 

 row. — Damp grounds, S. Car. to Fla. Sts. 1 to 3f high. Hds. small, with about 

 20 blue rays longer than the disk. Sept., Oct. (A. divaricatus Nutt.) 



3. 6xiLis. Taller, with fewer branches, eorymbed ; hds. racemed or solitary- 

 Rays pale purple. — Columbus, Ga. (A. exihs EU.) Height 2 to 4f 



19. DIPLOPAP'PUS, Cass. Double-bristled Aster. (Gr. dnrXooc. 

 double, TTaTTTToq, pappus.) Heads many-flowered ; vay-fiowers about 

 12, ? ; disk-flowers fj ; involucre imbricate, scales narrow, destitute of 

 green tips ; receptacle flat, subalvcolatc ; pappus double, tbe exterior 

 very short (about i" long), interior copious, capillary; achenia com- 

 pressed.— -2f Lvs. entire, alternate. Rays cyanic. Disk yellow. 



§ Rays violet. Achenia pilky. Bristles of the inner pappus alike No. J 



§ Eays whitish. Bomo of the longer bristles clavellate. — Ach. smoothish Nos. 2, .'^ 



— Ach. villous No. 4 



1 D. linaiiifolius Hook. St. straight, roughish; branches 1-flowered, fastigi- 

 ate ; scales imbricate, carinate, as long as the disk ; lvs. linear, entire, 1-veined, 

 muoronate, carinate, rough, rigid, thoso of the branches recurved. — A handsome 

 species, in dry woods, along streams, XT. S. and Can. Stems subsimple, purplish, 

 about a foot high. Leaves numerous, obtuse, with a small, mucronate point, shin- 

 ing above. Branehlets near the top, leafy, each with one rather large and showy, 

 violet-colorod head. Aug., Sept. (Aster, L.) 



2 D. umbellatus Hook. St. smooth, straight, simple ; hds. numerous, in a level 

 corymb ; lvs. long, lanceolate, smooth, acuminate at each end, rough on the mar- 

 gin ; invol. spales obtusely lanceolate ; ach. pubescent in lines. — Low grounds, river 

 banks, fields, N. Eng. to La. St. 3 to 4£ high (in dry fields but 1 to 2f) pur- 

 plish, channeled, branching at top into a large, level-topped, compound corymb. 

 Lvs. narrow, entire, 4 to 6' in length, those of the branchlets smaller. Rays about 

 12, white. IJisk yellow. Aug., Sept. (A. amygdaUnus Mx. A. umbellatus Ait) 



/3. AiiTOD.A.LiNua St. roughish above, green ; branches of the corymb divari- 

 cate ; lvs. broader. — Lower and less elegant than variety a. Common. 



3 D. coruifolius Less. St. smooth below, scabrous and slightly paniculate 

 above, few-flowered ; lvs. elliptical, thin, long-acuminate at both ends, entire, with 

 scattered hahs, rough-edged, invol. scales imbricate, shorter than the disk, obtuse; 

 ach. glabrous. — Grows in woods X. and M. States. Whole plant nearly smooth, 

 erect, 1 to 2f high. Lvs. paler beneath, on very short stalks or sessile. Fls. few, 

 large; outer scales very short. Eays about 10, white. Jl., Aug. (Aster, Muhl.) 



4 D. obovatus Torr. 4. Or. Cinerous-pubescent, corymbous above ; lvs. oblong- 

 obovate or elliptical, acute, sessile or the lower or short petioles, tomentous be- 

 neath; scales loose, linear-subulate, acute, in about 3 rows, downy, rusty yellow; 

 ach. silky-villous. — Damp shades, S. Car. to Fla. Height 2 to ?,t Lvs. longer 

 than the internodes (2 to 3'), rarely with a few teeth. Invol. broadly obconic. 

 Kaj'S narrow, white, spreading n'. Pappus rusty white. Sept., Oct. (Aster, Ell.) 



20. ERIG'ERON, L. Flea-bane. 'White-weed. (Gr. r/p, the spring, 

 yiptiiv, old man ; because it is soon hoary.) Heads many-flowered, sub- 

 hemispherical ; ray-floweis $ , very numerous (40 to 200), narrow, lin- 

 ear ; flowers of the disk v ; receptacle flat, naked ; scales of the invt- 



