SPARGANIACEAE 77 



Beaks straight or slightly curved; stigmas linear. 



Heads all axillary; beaks shorter than the bodies of 

 the achenes; leaves more or less keeled. 

 Achenes dull; stigmas 2 mm. long or less. 



Inflorescence branched. 2. 5. androcladum. 



Inflorescence mostly simple. 3. 5. americanum. 



Achenes glossy; stigmas 2.5-3.5 mm - l° n g- 4- S. lucidum. 



Heads, at least some of them, supra-axillary. 



Leaves, at least the middle ones, strongly tri- 

 angular keeled; stem erect. 5. 5. acaule. 

 Leaves not keeled; stem slender, usually 



floating. 6. 5. angustijolium. 



Beaks gladiate curved; stigmas short, oblong. 7. 5. fluctuans. 



Stipes and beaks less than 1 mm. long; fruiting heads about 



1.5 cm. in diameter or less. 8. 5." minimum. 



1. S. eurycarpum Engelm. Borders of water: Newf. to Fla., 



Cal. and British Columbia. 



Conn. Rare or local over most of the state, decreasing westward 



along the coast. 

 N. Y. Throughout, but rare; most common in the Hudson Valley. 

 N. J. Along the Delaware at Camden, increasing northward; not 



common. 

 Pa. From Northampton to Delaware counties. 



2. S. androcladum (Engelm.) Morong. Shallow water: Newf. 



to Fla., Ala. and Minn. 



Conn. Throughout, not common. 



N. Y. Throughout, apparently rare northward. 



N. J. Throughout, decreasing southward. 



Pa. Northampton to Delaware counties, not common. 



3. S. americanum Nutt. Bogs and muddy shores: Nova Scotia 



to S. Car., Indian Territory and Iowa. 



Conn. Throughout, not common. 

 N. Y. Throughout, apparently decreasing northward. 

 N. J. Throughout, apparently decreasing northward. 

 Pa. Philadelphia Co. 



4. S. lucidum Fernald & Eames. Ponds and streams : Mass. and 



N. Y. to Mo. and 111. 



Conn. Hartford and Southington. 



N. Y. Cypress Hills, L. I., and at Jamaica (according to Bicknell). 



5. S. acaule (Beeby) Rydberg. Muddy shores and swamps: 



Newf. to Va., Iowa and S. Dak. 



