DiPLOPAPPus. COMPOSITiE. 351 



long as the corolla ; the exterior very short, setaceous or subulate. — Perennial herbs or 

 suffruticose plants, of various habit, vyith alternate, mostly entire sessile leaves. Heads 

 corymbose, or terminating the simple branches. Rays blue, purple or white ; the corolla 

 of the disk yellow^, rarely turning to purple. 



§ 1. Ianthe, Terr. & Gr. Bristles nf the inner pappus not elavellate or thickened at the tip ; the 

 exterior setaceous : achenia villous or silky, linear, somewhat compressed : involucre about the 

 length of the disk : leaves crowded, linear, rigid, one-nerved, mucronate, with very rough 

 margins : heads terminating the simple branches. 



1. DiPLOPAPPus LiNARiiFOLius, Hook. Narrow-leaved Diplopapp}is. 



Stems strict, usually several from one root, or branching at the base ; leaves linear, rigid, 

 spreading ; scales of the turbinate involucre rigid, carinately one-nerved, the exterior short 

 and acute, the interior mostly obtuse ; achenia silky villous. — Hook. fl. Bor.-Am. 2. p. 21 ; 

 Darlingt. fl. Cest. p. 743 ; Torr. <^ Gr. fl. N. Am. 2. p. 181. D. linariifolius and rigidus, 

 Lindl. in DC. prodr. 5. p. 277. Diplostephium linariifolium, Nees, Ast. p. 199. Chrysopsis 

 linariifolia, Nutt. gen. 2. p. 152. Aster linariifolius, Linn. sp. 2. p. 874 ; Michx. fl. 2. p. 

 110 ; Pursh, fl. 2. p. 545 ; Ell. sk. 2. p. 365 ; Bigel. fl. Bast. p. 309 ; Beck, hot. p. 187. 

 A. rigidus, Linn. I. c. ; Michx. I. c. ; Pursh, I. c. A. pulcherrimus, Lodd. bat. cab. 1. t. 6. 



Stems 8 — 18 inches high, growing in clusters, erect or assurgent, reddish, puberulent, the 

 lower part either simple or divided near the root, with very few or numerous corymbose 

 branches at the summit ; the peduncles or flowering branches usually somewhat elongated 

 (often with small bract-like leaves), or frequently short and in a compact cluster. Leaves 

 about an inch long and a line wide, crowded, sometimes reflexed, the margin very rough with 

 minute prickles. Heads large and showy. Scales of the involucre ciliate, finally a little 

 spreading; the inner ones purplish at the tip. Rays 10 - 12, violet, twice as long as the 

 involucre. Exterior pappus copious. Achenia small. 



Dry open woods and on hill-sides ; common. August - October. A humble but ornamental 

 species. 



^ 2. Triplopappus, Torr. &, Gr. Bristles of the inner pappus unequal, some of them elavellate or 

 thickened at the summit, the exterior of somewhat scale-like bristles : achenia obovoid, compressed, 

 imooth or slightly pubescent, 5 - Q-nerved : involucre shorter than the disk : leaves lanceolate, 

 ovate or oblong : rays lohite. 



2. DiPLOPAPPus coRNiFOLius, Darlingt. Cornel-leaved Diplopappus. 



Stem slender, roughish-pubescent, rather naked and sparingly corymbose-paniculate at the 

 summit ; leaves elliptical, acuminate at each end, hairy on the veins underneath ; heads few, 

 on divaricate pedicels ; achenia smooth. — Darlingt. fl. Cest. p. 474 ; Torr. <^ Gr.fl. N. Am. 

 2. p. 182. Doellingeria cornifolia, Nees, Ast. p. 181. Diplostephium cornifolium, DC. prodr. 



