AsTBR. COMPOSITE. 349 



Stem 12-18 inches high, rather stout, angular, more or less pubescent or sometimes hairy. 

 Leaves 3-6 inches long and 1-2 inches wide, tapering from about the middle to a cuneate 

 entire base, pinnately veined, the teeth mucronate and spreading. Heads commonly few, in 

 a loose spreading paniculate corymb. Involucre nearly half an inch in diameter : scales pale 

 green or tinged with purple, tapering to a long narrow point , the outer ones much smaller. 

 Rays 12 - 18, elongated, white. Achenia narrowly oblong, clothed with a short glandular 

 pubescence. 



In fertile woods, and on mountains ; rather common in the northern and southwestern 

 counties, and on the Hudson as far south as Catskill. August - October. 



24. Aster ptarmicoides, Torr. 8f Gr. (Plate LII.) Ptarmicoid Aster. 



Stem simple, rough above ; leaves linear-lanceolate, rigid, acute, somewhat shining, very 

 rough on the margin , those of the stem entire ; the lower ones elongated, often slightly and 

 remotely toothed, tapering to the base or somewhat petioled ; corymb fastigiate ; scales of the 

 hemispherical involucre closely imbricated, rather obtuse, shorter than the disk. — Torr. ^ 

 Gr. fl. N. Am. 2. p. 160. Chrysopsis alba, Nutt. gen. 2. p. 152. Doelingeria ptarmicoides, 

 Nees, Ast. p. 183. Diplopappus albus, Hook. fl. Bor.-Am. 2. p. 21 ; Gray in ann. lye. N. 

 York, 3. p. 226. Heleastrum album, DC. prodr. 5. p. 264. Bucephalus albus, Nutt. in 

 trans. Amer. phil. soc. (n. ser.) 7. p. 299. 



Stems 6-18 inches high, commonly several from a somewhat woody rhizoma. Leaves 

 usually a little ciliate at the base, more or less rough ; the lower and radical ones 3-6 inches 

 long and 2-4 lines wide, with a long tapering base, and often distinctly petiolate. Heads 

 rather small, in a spreading flat-topped corymb. Scales of the involucre narrowly oblong, 

 nearly smooth, greenish, in 3 - 4 unequal series. Rays 12 - 18, white. Pappus soft and 

 white ; the longer bristles thickened at the apex. 



Rocky banks of the Black River, near Watertown, Jeflferson county. July - September. 

 A rare and singular species, which has been referred to six difiierent genera, but is a genuine 

 Aster. 



^5. OxTTRiPOLiuM, DC; Torr. & Gr. Scales of the involucre membranaceous or chartaceous with 

 membranaceous margins, destitute of herbaceous tips, usually very acute, the exterior passing 

 into scale-like bracts : receptacle somewhat alveolate : bristles of the pappus soft and capillary, 

 nearly equal : achenia compressed, often striate : leaves thickish or succulent, narrow and entire. 

 —Annual or perennial ; mostly smooth; natives of salt marshes. 



25. Aster flexuosus, Nutt. Perennial Salt-marsh Aster. 



Stem very smooth, flexuous, sparingly branched, the branches mostly terminated by (large) 

 solitary heads ; stem-leaves linear , the lower ones lanceolate-linear, elongated, fleshy, acute, 

 tapering to the base , those of the branchlets subulate ; scales of the campanulate involucre 



