The Flora of the Cayuga Lake Basin 287 



Most abundant about the ravines of the basin. Occurring also on the Caroline hills, 

 in Michigan Hollow, on South Hill, and in Newfield, Mecklenburg, and elsewhere. 

 Absent in the McLean region and on the clays and richer soils back from the lake 

 shores. 



E. Que. to Man., southw. to Ga., 111., and Minn., but rare on the Coastal Plain. 



Individuals with white flowers have been reported from several localities. 



2. P. Senega L. Seneca Snakeroot. 



Steep slopes and rocky ledges, in rich calcareous clay-gravel or talus soils ; fre- 

 quent. May 15-June 15. 



Bald Hill, Caroline, and Caroline Pinnacles (D.) ; Inlet Valley, Newfield-Ithaca 

 town line; ravine n. of Buttermilk Glen; Coy Glen; Six Mile Creek (D. !) ; 

 Beebe Lake; e. of Forest Home; Renwick slope; ravines of Cayuga Lake (D.) ; 

 lake cliffs n. of Ludlowville; King Ferry; Paine Creek; Big Gully; especially 

 frequent on ravine banks and along the Cayuga Lake shore. Absent in the McLean 

 region. 



N. B. to Hudson Bay and Alberta, southw. to N._ C. along the mts., and to Mo. 

 and Ark. ; rare or absent on the Coastal Plain and in granitic N. E. 



3. P. SANGUINEA L. 



Open fields, in damp, sandy, poorly drained, acid soils ; scarce. July-Aug. 



Pasture, n. w. corner of Michigan Hollow Swamp ; hill w. of West Danby ; 

 border of Slaterville Swamp; fields just n. of South Hill Marsh above and below 

 wooded terrace ; pasture e. of McLean Bogs ; Junius ; near Montezuma Marshes. 

 Probably of recent introduction in this region. First collected at Michigan Hollow by 

 Rowlee and Wiegand in 1893. 



N. S. to Ont. and Minn., southw. to N. C, La., and Kans., including the Coastal 

 Plain. 



4. P. verticillata L. 



Dry open sunny slopes, in sandy or gravelly, neutral or acid, soils ; frequent. 

 July-Sept. 



Pasture n. of Spencer Lake; Key Hill; Enfield Glen; Coy Glen; South Hill; 

 Fall Creek, e. of Forest Home ; s. slope of Turkey Hill ; Esty Glen ; n. e. of 

 Shurger Glen ; gravelly bank w. of Lowery Ponds ; absent in the McLean region. 



Me. to Sask., southw. to Fla., La., and Mex., including the Coastal Plain. 



4a. P. verticillata L., var. ambigua (Nutt.) Wood. 



Old flatland pastures ; rare. 



Between Spencer Lake and Summit Marsh near base of east hill, 1916, and per- 

 sisting since. 



Me. to Mich., southw. to Ga. and La. 



Sepals and persistent part of spike slightly longer than in the typical form. 



73. EUPHORBIACEAE (Spurge Family) 



a. Ovary sessile ; flowers with a calyx and no involucre, each pistillate flower sub- 

 tended by a large lobed bract; juice not milky. 1. Acalypha 



a. Ovary apparently stalked ; a stalked pistillate flower and several staminate 

 flowers together, surrounded by a cup-shaped involucre provided with glands ; 

 juice milky. 2. Euphorbia 



1. Acalypha L. 

 1. A. virginica L. Three-seeded Mercury. 



A weed in dry open fields and by roadsides, in gravelly or sandy noncalcareous 

 soils ; common. Aug-Sept. 



