The Flora of the Cayuga Lake Basin 407 



Que. and N. S. to Wis., southw. to Fla. and Tex., including the Coastal Plain. 



The local material has only slightly hairy stems. Three forms occur: (1) with 

 the subsessile heads densely arranged, rare (probably typical A. lateriflorus) ; (2) 

 with the heads more loosely arranged, the more common form (probably A. 

 diffusus Ait.) ; (3) with the involucral bracts more dilated at the tips and the more 

 conspicuous reduced leaves on the peduncles firmer and more obtuse, occasional 

 (possibly A. horizontalis Desf.). Plants of the last-named form from the Cayuga 

 Lake Basin are not extreme, and are intermediate between the other forms and no. 

 3 as found along the coast. Bog plants of form no. 2 often have narrower, nearly 

 linear, leaves. Dudley's A. diffusus, var. thyrsoideus, cannot be identified with 

 certainty. 



16. A. paniculatus Lam. (A. Tradescanti and A. paniculatus of Cayuga Fl.) White 



Field Aster. 



Damp or rather dry roadsides and thickets ; common, especially in heavy soil. 

 Sept.-Oct. 



Que. to Mont., southw. to Va., La., and Mo. ; infrequent on the Coastal Plain. 



Exceedingly variable as to habit, density of inflorescence, size of heads, length of 

 rays, and size and shape of leaves. An attempt has been made to separate the 

 smaller-headed forms, as A. Tradescanti, from those with larger heads {A. panicu- 

 latus), but the intermediates are as numerous as, if not more numerous than, the 

 extremes. So far, it has not been possible to draw any lines in the local material 

 between the multitude of forms of this species, or to find any factors with which 

 the forms are connected. It has seemed best to employ the name A. paniculatus 

 for the local plants, as the exact status of A. Tradescanti is in doubt; the latter 

 species may still be distinct elsewhere, and possibly based on other characters. 



17. A. umbellatus Mill. 



Edge of woods and thickets, in low mucky soils, rarely on wet rocks and talus ; 

 common. Aug. 10-Sept. 15. 



Newf. to Sask., southw. to Ga., Mich., and Iowa, including the Coastal Plain. 



18. A. acuminatus Michx. 



Dry or damp woodlands in humus ; frequent at the higher elevations. Aug.-Sept. 



Spencer; Danby (D. !) ; Newfield (D.\) ; upper Coy Glen; Six Mile Creek (D.) ; 

 Caroline (D.) ; Ringwood ; Dryden Lake; McLean region; Junius. Especially 

 abundant in tracts recently cleared. 



Lab. to Ont, southw. to Pa. and in the mts. to Ga. ; rare or absent on the Coastal 

 Plain. 



7. Erigeron L. 



a. Rays much exceeding the disk, conspicuous ; heads of medium size or large. 

 b. Heads 2.5-3.5 cm. in diam. ; rays 1 mm. wide, blue; leaves oblong-lanceolate. 



1. E. pulchellus 

 b. Heads 1.5-2 cm. in diam.; rays 0.8 mm. wide or less. 



c. Rays 100-150, pink; cauline leaves oblong, clasping. 2. E. philadelphicus 



c. Rays 50-75, white ; cauline leaves lanceolate to linear, narrowed and not 

 clasping at base. 

 d, Leaves toothed or entire, firm ; pubescence strigose. 3. E. ramosus 

 d. Leaves coarsely toothed, thin; pubescence, if any, scattered and hispid. 



4. E. annuus 

 a. Rays scarcely exceeding the disk, inconspicuous ; heads very small and numerous, 

 in a thyrsoid panicle. 5. E, can-adensis 



