168 COMPOSITE. 



the same color on both sides; lower serrate in the middle; upper clasping, 

 entire ; scales of the involucre imbricate, lanceolate. 



Fields and woods. N. J. to Car. Aug. Oct. '7J.. Stem, 2 feet high. Heads 

 large and very numerous, clustered towards the summits of the branches ; rays 

 white, changing to a deep violet ; disk yellow. Pursh. A doubtful species. 



Various-colored Aster. 



32. A. Greenii Torr. fy Gr. : stem very smooth, racemosely branched or 

 compound ; leaves nearly all remotely appressed-serrulate, smooth, acute or 

 acuminate, rough above ; cauline narrowly lanceolate, elongated, slightly 

 clasping (not dilated) at the base, spreading ; heads simply racemose on the 

 leafy branches, on short bracteate peduncles ; scales of the campanulate 

 involucre linear-lanceolate, acute, rather closely imbricate. 



Fields. Boston, Mass. Dr. Greene. Schenectady, N. Y. Tuckerman. 

 Heads racemose or crowded on the slender branches ; rays rather short, pur- 

 plish ; disk turning to reddish-purple. Greene's Aster. 



33. A. elodes Torr. fy Gr. : very smooth ; stem simple or sparingly 

 branched, slender ; leaves varying from lanceolate to linear, somewhat co- 

 riaceous, narrowed at each end, nearly entire or serrulate, shining ; upper 

 somewhat clasping by a narrow base ; scales of the hemispheric involucre 

 spatulate-linear, acute, mucronulate, with recurved-spreading herbacepus 

 tips. A. paludosus Nutt. 



Swamps in pines. Mass, to Car. Aug. Oct. %.. Stem 1 2$ feet high, 

 flexuous, simple, with a few flowers in a paniculate raceme at the summit, or 

 somewhat oompoundly branched above with the flowers more numerous. 

 Heads large, seldom numerous, solitary on the shortish branchlets ; rays large, 

 deep blue or violet ; disk yellow, sometimes turning purplish. (Torr. N. Y. Fl.) 



Blue Smooth Marsh Aster. 



**** Scales of the regularly imbricate involucre with membranaceous m 

 scari&us margins, destitute of herbaceous tips. Receptacle alveolate, Jlat. 

 Bristles of the pappus capillary, mostly unequal. ORTHOMERIS Torr. $* Gr. 



34. A. acuminatus Mich. : stem simple, flexuous, pubescent, or hairy, 

 loosely and paniculately corymbose at the summit; peduncles slender, 

 naked ; leaves broad cuneiform-lanceolate, membranaceous, conspicuously 

 acuminate, unequally serrate above, tapering and entire towards the base, 

 smooth above, pubescent beneath ; scales of the involucre loosely imbri- 

 cate, linear, acuminate. 



In woods, and on mountains. Can. to Virg. Aug. Oct. 1\.. Stem 1218 

 inches high, stout. Heads usually few, middle-sized ; rays white, sometimes 

 tinged with purple. Acuminate-leaved Aster. 



35. A. ptarmicoides Torr. <$ Gr. : stem simple, rough above ; leaves 

 linear-lanceolate, rigid, acute, somewhat shining, very rough on the mar- 

 gin ; cauline entire; lower elongated, often slightly and remotely toothed, 

 tapering at base or somewhat petioled ; corymb fastigiate ; scales of the 

 hemispheric involucre closely imbricate, rather obtuse, shorter than the 

 disk. Chrysopsis alba Nutt, Diplopappus albus Hook. Hekastrum album 

 D. C. 



Rocky banks. Can. Ver. and N. Y. W. to Fort Mandan. July Serit. Tj, 

 Stems 6 18 inches high, slender, usually several from one root. Heads rather 

 small, in a fastigiate corymb; rays white. From Dr. Torrey's figure in his 



