Sparganium 



Sparganiaceae 



73 



^50 



Map 71 



Sparganium eurycarpum Engelm. 



"50 



Map 72 

 Sparganium androcladum 



(Engelm.) Morong 



Leaves soft and mostly translucent, flat or obscurely keeled; inflorescence simple 

 or, if branched, the branches strict with 1-3 pistillate and 1-6 staminate 

 heads; stigmas 1-2 mm long; fruiting heads 1.5-2.5 cm in diameter; achenes 

 slightly lustrous, the body 4.5-5.5 mm long, about 2 mm thick; anthers 



0.8-1.2 mm long o. S. americanum. 



Pistillate heads usually supra-axillary; achenes shining, the beak more gradually 



narrowed upward; leaves 3-9 mm wide with a scarious margin near the base. 



Plants commonly erect and emersed; leaves flat or slightly keeled, little, if at 



all, dilated at the base (except for the scarious margin) ; staminate half of 



the inflorescence 2-10 cm long, of 4-9 scattered heads (if shorter and with 



fewer leads, the plant very low and with ribbonlike, translucent, erect, lower 



bracts) ; beak of achenes 2-4.3 mm long; sepals appressed, cuneate-spatu- 



late, scarcely narrowed to a claw. 



Pistillate heads (1) 2-4, remote or subremote, at maturity 1.5-2.7 cm in 



diameter, the lowest borne 1-6.5 dm above the base of the plant; staminate 



half of the inflorescence 2-10 cm long, of 4-9 heads 4. S. chlorocarpum. 



Pistillate heads 1-3, at least the upper usually approximate, at maturity 

 1.2-2.2 cm in diameter, the lowest borne 0.1-1.8 dm above the base of the 

 plant; staminate half of the inflorescence 1-4 (5) cm long, of 2-5 heads. 



4a. S. chlorocarpum var. acaule. 



Plants commonly submerged or floating, sometimes emersed; leaves rounded on 

 the back, the middle and upper with dilated and subinflated sheathing 

 bases; staminate half of the inflorescence 1-3 cm long, of 1-4 (rarely 6) 

 crowded heads; beak of achene about 2 mm long; sepals loosely ascending, 

 with slender claw and dilated tip. (See excluded species no. 26, p. 1023.) 



S. angusti folium. 



Staminate head 1; fruiting heads 5-12 mm in diameter; achenes ellipsoid or 

 slenderly obovoid-fusiform, 3.5-5 mm long; stipe obsolete or up to 1 mm long, 

 beak obsolete or up to 1.5 mm long; inflorescence simple, the heads all axillary; 

 sepals elliptic to cuneate-spatulate, a half to two thirds as long as the achene; 

 plants usually floating. (See excluded species no. 27, p. 1023.) . . . .S. minimum. 



1. Sparganium eurycarpum Engelm. Giant Bur-reed. Map 71. Infre- 

 quent to frequent in the lake area and rare or possibly absent from the 

 southern part of the state. There are only three reports for it south of 

 Hamilton County, and it is barely possible that these should be referred 

 to the next species. It is found in wet places, mostly in ditches. It also 



