COMPOSITiE. 194 DIPLOPAPPUS. 



obsoletely 3-nerved, roup-h on the margin. About2 feet high, with pale green 

 foliage and a terminal, level-topped corymb of small white flowers. Grows 

 in woods. Stem slender, smooth, simple. Leaves smooth. Involucre im- 

 bricate, oblong, with appressed scales. Rays long, white. Jl. Aug. 



2. S. CONVZOI'dES. Mes. Conyzaasteroides. L. Aster conyzcides. JFjVW. 



Slein somewhat pubescent, simple, corymbose at top ; leaves oval-lanceolate, 

 smooth beneath, slightly 3-nerved, narrowed at base, acute, the upper ones 

 sessile, nearly entire, the lower narrowed into the petiole, serrate; involucre 

 cylindrical, the scales oval, obtuse, appressed, slightly reflexed at summit; 

 rays 5, short. Grows in woods and thickets. Stems somewhat 5-angled, 1 — 

 2 teet high. Leaves somewhat fleshy, Ray short, but longer than the 

 disk, white, July. August. 



11. DIPLOPA'PPUS. 

 Heads many-flowered ; ray fls. about 12, pistillate ; diskfls. 

 perfect; involucre imbricate; receptacle tlat, subalveolate ; 

 pappus double, the exterior very siiort, interior copious, capil- 

 lary ; achenium compressed. 



Gr. }i7rXooi. double, TuTTroi, pappus. Perennial herbs, with alternate and 

 entire leaves.' Rays cyanic; disk yellow. Inner pappus about as long as 

 the tube of the corolla, 



1. D. LINARIFO'LIUS. Hook. Aster linarifolius. L, 



Stem straight, roughish; branches 1-flowered, fastigiate ; scales oi involucre 

 imbricate, carinate, as long as the disk ; leaves linear,entire,l-nerved,mucro- 

 nate, carinate, rough, rigid, those of the branches recurved. . A rough, rigid, 

 leafy species, growing in dry pastures, woods, West River Mt., &c. Stems 

 subsimple, purphsh, about a foot high, decumbent at base. Leaves numerous, 

 rigidly upright or deflected, obtuse, with a small, mucronate point, pale 

 beneath, shining above. Branchlets near the top, leafy, each with one rather 

 laroe and showy, violet-colored flower. Aug. Sept. 



Linear -leaved Dijilopappus. 



2. D. UMBELLA'TUS. T. S,- G. Aster umbellatus. .,iit. 



Stem smooth, straight, simple ; corymb fastigiate ; leaves long, lanceolate, 

 smooth, attenuate-acuminate at each end, rough on the margin ; involucre 

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

 river banks and fields. Stem 3—4 feet high (in dry fields but 1—2), purplish, 

 channelled, simple, smooth, branching above into a large, level-topped, com- 

 pound corymb of showy flowers. Leaves narrow, entire, 4 — U inches in length, 

 those of the branchlets smaller. Rays about 12, white. Disk yellow. Aug. 

 September. Umbellate Diplopappus. 



3. D. CORNIFo'LIUS. Darlington. Aster cornifolius. L. 



Stem smooth below, scabrous and slightly paniculate above, few-flowered; 

 leaves elliptical, acuminate, entire, tapering to the base, with scattered hairs, 

 rouifh-edged ; involucre scales imbricate, shorter than the disk. Grows in 

 woods, common. The whole plant nearly smooth, erect, 1—2 feet high. 

 Leaves acute at the base, paler beneath, on very short stalks. Flowers lew, 

 laro-e ; outer scales very short. Rays about 10, white, Jl. Aug. 



