416 Karl M. WiegAnd and Arthur J. Eames 



1. H. divaricatus L. Wild Sunflower. 



Dry open woods and thickets, in sandy or gravelly noncalcareous soils ; com- 

 mon. Aug.-Sept. 



On the more residual acid soils of the hills w., s., and s. e. of Ithaca, on the 

 ravine crests and the crests of the cliffs along Cayuga Lake, and in the sandy 

 regions n. of the lake; rare or absent in the McLean region and in the clays and 

 richer soils back from the lake shores. 



S. Me. to Man., southw. to Fla., La., and Nebr. ; common along the coast. 



Apparent hybrids with H. strumosus or H. decapetalus occur on Farley Point. 



2. H. strumosus L. Wild Sunflower. 



In open woods or thickets, on damp or rather dry rich banks; frequent. 

 Aug.-Sept. 20. 



Cascadilla woods; Beebe Lake; King Ferry (£>.) ; Lockwood Flats (V.) ; Union 

 Springs ; Tunius ; and elsewhere. 



N. E. to Ont. and Minn., southw. to Ga., Tenn., and Ark., including the Coastal 

 Plain. 



"A stout, broad and hairy leaved form, south of Ithaca and near Cayuga Bridge" 

 (D.) is possibly var. mollis T. & G. 



3. H. decapetalus L. Wild Sunflower. 



Thickets on low alluvial soils or on the richer talus at the base of ravine cliffs, 

 rarely in more exposed places; common, and generally distributed. July 25-Sept. 



Me. and w. Que. to Minn., southw. to Ga., Tenn., and Mo. ; rare or absent on 

 the Coastal Plain. 



4. H. tuberosus L. Jerusalem Artichoke. 



Roadsides, fence corners, and similar situations, in rich moist soil ; frequent, and 

 widely distributed. Sept.-Oct. 



Adventive, or escaped from gardens, probably not native. 



N. S. to Ont., southw. to Ga., Ark., and Kans. 



Forms intermediate between this species and H. decapetalus are found along the 

 lake shore, especially from Ledyard to Union Springs. These plants are very 

 possibly hybrids of the two species. Dudley says, "the escaped hairy form, near 

 Ithaca and Cayuga L. shore, on Lockwood's Flats and elsewhere." Some plants 

 from a garden in Ithaca would seem to indicate that the cultivated form is really 

 often hirsute. 



[H. annuus L. Common Sunflower. 



Commonly cultivated and occasionally springing up in waste places, but not 

 established. 



Native: Minn, to Idaho, southw. to Tex. and Calif.] 



19. Bidens L. 



a. Plant aquatic ; submerged leaves finelv dissected ; rays showy. 



1. B. Beckii 

 a. Plant terrestrial. 



b. Achenes linear-spindle-shaped, tapering to a slender apex, 4-grooved and with 



3-4 short awns; rays very short. 2. B. bipinnata 



b. Achenes not as above. 

 c. Rays large and showy. 

 d. Leaves simple ; achenes flat or 3-4-angled ; awns 2-4, downwardly barbed ; 

 heads often cernuous. 



