212 ARACEAE 



N. J. Sussex and Salem counties; reported also from Bergen Co. 

 Pa. Montgomery Co. ; reported from Bucks, Northampton and 

 Delaware counties. 



Dichromena colorala (L.) Hitchc, once supposed to grow in N. J., has not bein col- 

 lected from there recently, if at all. The original record from the state is apparently 

 an error. 



ARACEAE 



Flowers without a perianth. 



Flowers monoecious or dioecious. 



Flowers borne at the base of the spadix. i. Arisaema. 



Flowers borne throughout the spadix. 2. Peltandra. 



Flowers perfect. 3- Calla. 



Flowers with a perianth. 



Spathe enclosing the spadix. 4- Spathyema. 



Spathe, when present, not enclosing the spadix. 



Spadix naked terminating the scape; leaves oblong. 5. Orontium. 



Spadix borne at the base of a leaf-like spathe; leaves linear. 6. Acorus. 



i. Arisaema Mart. 



Spathe hooded, open at the throat, enclosing the spadix; leaves 

 tri-foliolate. 

 Leaves glaucous beneath; spadix stout, thickening upward. I. A. iriphyllum. 

 Leaves shiny throughout; spadix slender, cylindric. 



Spathes light colored, distinctly fluted, flaring into a re- 

 latively broad hood. 2. A. Stewardsonii. 

 Spathes dark colored (except in rare albino forms) the tube 



not fluted and not much narrower than the hood. 3. A. pusiUum. 



Spathe convolute; summit of spadix exserted; leaves pedately 5-17 

 divided. 5- -4- Dracontium. 



i. A. triphyllum (L.) Torrey. In rich woods and moist thickets: 

 Nov. Scot, to Fla., Ont., Minn., Kan. and La. 

 Conn. Common throughout. 



N. Y. Common throughout, but rare south of the moraine on L. I. 

 N.J. Rare and local, or often wanting in the pine-barrens, common 



elsewhere. 

 Pa. Common throughout. 



Tertiary, rare on Beacon Hill, scattered elsewhere: Cretaceous, 

 more common: Older formations, ubiquitous. 1 17-204 days. 

 Sea level-3,365 ft. 



2. A. Stewardsonii Britton. In wet woods, growing among 

 sphagnum: N. J. and Pa. 

 N. J. Morris and Sussex counties. 

 Pa. Wayne, Pike, Monroe and Luzerne counties. 



Tertiary, O: Cretaceous, o: Older formations, increasing at 



