186 DICOTYLEDONOUS PLANTS. 



36. A. tradescanti Linn. : stem terete, smooth ; branches virgate ; 

 leaves lanceolate, serrate, sessile, smooth ; involucre imbricate 



HAB. Dry swamps. Can. to Virg. Aug. Oct. I(. Stem 

 3 4 feet high. Flowers very small ; rays white or purple. A. re- 

 curoatus of Willdenow, is considered by Dr. Torrey as a mere 

 variety of the above. It has the leaves narrower and the panicle 

 sometimes recurved. 



37. A. eminens W\Ud. : stem paniculate ; branchlets 1 -flowered ; 

 leaves linear-lanceolate, acuminate, scabrous on the margin ; lower 

 ones subserrate ; involucre imbricate ; scales lanceolate and A. laws. 



wilid. 



HAB. Fields. N. J. to Virg. Sept. Nov. 2^. Fhicers middle- 

 sized ; rays pale, lilac ; disk yellow, changing to red. As sug- 

 gested by Mr. Nuttall, A. laxug of Willdenow is scarcely to be 

 distinguished from this species. 



38. A. simplex If 'Hid. : stem very smooth, paniculate at the summit : 

 leaves lanceolate, acuminate, scabrous on the margin ; those of the 

 stem serrate at the apex, of the branches very entire ; involucre loose- 

 ly imbricate ; scales linear-subulate. 



HAB. Penn. Torr. If. Rays white ; disk yellow. Pvrsh. 



39. A. polyphyllus Willd. : stem much branched, pubescent ; leaves 

 linear, very entire ; radical ones oblong, subserrate ; involucre loosely 

 imbricate. 



HAB. Penn. Ttnr. 11. Rays white ; disk yellow, changing to 

 red or brown. Pvrsh. 



40. A. junccus Ait. : stem paniculate, smooth ; branches virgate ,- 

 leaves lanceolate-linear, sessile, smooth ; lower ones subserrate ; those 

 of the branches lanceolate ; involucre imbricate. 



HAB. Low grounds. N. 8. Aug. Oct. If. Stem 46 feet 

 high. Flowers flesh coloured. A lanceolatus of Willdenow, is 

 only a variety with a branched stem and smaller flowers. 



41. A.fragilis Willd.: <tem smoothish ; branches corymbose-pani- 

 culate ; leaves linear, acuminate, very entire ; radical ones oblong, 

 serrate ; involucre imbricate ; scales appressed. 



HAB. Fields. N. S. Sept. !(. Stem 2 feet high. Flovtrs 

 small, white. 



42. A. miser Linn. : stem villous ; leaves sessile, lanceolate, serrate, 

 smooth ; involucre imbricate; scales acute ; disk equal to the ray. 



a. diver gens ; leaves elliptical-lanceolate. A. ditergens Ait. 



b. diffusus ; leaves all proportioned . A. diffusus Ait. 



c. pendulus; leaves of branches rather remote. A. pmdulus Ait. 

 HAB. Fields. N. S. Aug. Nov. If. Flowers small, white. 



I follow Dr. Torrey in uniting the above species with A. miser. 



3. Leaves cordate and orate, serrate. 



43. A. undulatus Linn. : stem paniculate, hispid ; branchlets second, 

 leaf/, 1 -flowered ; leaves oblong, cordate, clasping, very entire, hairy, 



