DIPLOPAPPUS. LXXV. COMPOSITE. 325 



a spreading panicle of heads which are below the middle size and furnished 

 with snow-white rays. July Sept. 



41. A. FLEXUOSUS. Nutt. (A. sparsiflorus. Ph.} Few-flowered Aster. 



St. branching, slender, flexuous, very smooth ; Ivs. long and succulent, the 

 lower ones sublanceolate-linear, upper ones subulate; branches leafy, 1-flow- 

 ered; invol. scales lanceolate, acuminate, appressed; rays numerous, shorter 

 than the involucre. Grows in salt marshes, Mass, to Flor. The whole plant 

 very smooth, If high, with large, purple flowers; disk yellow. Aug. Oct. 



42. A. LINIFOLIUS. (A. subulatus. Michx.} Sea Aster. 



St. paniculate, much branched from the base ; Ivs. long, linear, very acute, 

 the uppermost subulate ; mwZ.^cylindric with subulate scales ; radical hds. mi- 

 nute. An annual species, found in salt marshes, Mass, to Car. Stem 12 18' 

 high, very smooth, thick, reddish. Leaves smooth, sessile. The plant is very 

 branching, with numerous short-rayed, small, purple flowers. Aug. 



11. SERICOCARPUS. Nees. 



Gr. oriptKos, silken, ap7roj, fruit; from the character of the genus. 



Heads few-flowered; ray-flowers 4 6, 9; disk-fls. 6 10, $; in- 

 volucre oblong, imbricated ; scales appressed, with green, spreading 

 tips ; receptacle alveolate ; achenium obconic, very silky ; pappus 

 simple. ^ Herbs with alternate leaves and close corymbs. Rays white. 



1. S. SOLIDAGINEUS. Nees. (Aster solidaginoides. Michx.} 



Smooth ; Ivs. linear-lanceolate, obtuse, entire, sessile, obsoletely 3- veined, 

 rough on the margin ; corymb fastigiate ; Ms. aggregate, subsessile, 5-rayed ; 

 scales obtuse, white, with green tips. In woods, Can. to La. Not common. 

 Stem slender, simple, about 2f high. Leaves smooth, pale green, 1 2' by 3 

 5". Heads rather small, in a level-topped corymb. Involucre oblong. Scales 

 imbricate, appressed, with conspicuous green tips. Rays long, white. Jl. Aug. 



2. S. coNYzolDEs. Nees. (Aster. Willd. Conyza asteroides. Linn.} 



St. somewhat pubescent, simple, corymbose at top ; Ivs. oval-lanceolate, 

 smooth beneath, slighly 3-veined, narrowed at base, acute, the upper ones ses- 

 sile, nearly entire, the lower narrowed into the petiole, serrate ; invol. cylindri- 

 cal, the scales oval, obtuse, appressed, slightly reflexed at summit ; rays 5, short. 

 Common in woods and thickets, Mass, to Flor. Stems somewhat 5-angled, 

 1 2f high. Leaves somewhat fleshy. Ray short, but longer than the disk, 

 white. July, Aug. 



12. DIPLOPAPPUS. Cass. 



Gr. JiTrXooj, double, TTaTTTrof, pappus; from the character. 



Heads many-flowered: ray-fls. about 12, 9; disk-fls. ; involucre 

 imbricate ; receptacle flat, subalveolate ; pappus double, the exterior 

 very short, interior copious, capillary ; achenium compressed. % 

 Lvs. entire, alternate. Rays cyanic. Disk yellow. 



1. D. LINARIIFOLIFS. Hook. (Aster linariifolius. Linn.} 



St. straight, roughish ; branches 1-flowered, fastigiate ; scales of invol. im- 

 bricate, carinate, as long as the disk ; Ivs. linear, entire, 1-veined, mucronate, 

 carinate, rough, rigid, those of the branches recurved. A handsome species, 

 in dry woods, along streams, U. S. and Can., rather rare. Stems subsimple, 

 purplish, about a foot high, decumbent at base. Leaves numerous, rigidly up- 

 right or recurved, obtuse, with a small, mucronate point, pale beneath, shining 

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

 violet-colored head. Aug. Sept. 



2. D. UMBELLATUS. Hook. (A. amygdalinus. Michx. A. umbellatus. Ait.} 

 St. smooth, straight, simple; corymb fastigiate; Ivs. long, lanceolate, 



smooth, attenuate-acuminate at each end, rough on the margin ; invol. scales 

 obtusely lanceolate. A tall, handsome plant, growing in low grounds, river 

 banks and fields, N. Eng. to La. Stem 3 4f high (in dry fields but 12), 



