Genus i. 



BUR-REED FAMILY, 



Narrow- 



10. Sparganium angustifolium Michx. 

 leaved Bur-reed. Fig. 170. 



Sparganium angustifolium Michx. Fl. Bor. Am. 2: 189. 



1803. 

 Sparganium natans angustifolium Pursh, Fl. Am. Sept. 34. 



1814. 

 Sparganium simplex angustifolium Torr. Fl. N. Y. 2 : 249. 



1843. 



Stem floating and elongated, or occasionally i°-i° 

 high; leaves usually very narrow, i4"-2" wide, not 

 keeled ; bracts various, the lower ones similar to the 

 leaves, dilated and sometimes slightly scarious-margined 

 at the base, the upper ones much shorter than the lower, 

 lanceolate to ovate; inflorescence simple, the pistillate 

 heads 2-4, the lower I or 2 usually on supra-axillary 

 peduncles, the staminate heads usually approximate ; 

 fruiting heads 7"-8" in diameter; nutlets dirty-brown, 

 except the reddish brown bases, the body constricted at 

 the middle or above it; stigma i" long or less. 



In slow streams and ponds, Newfoundland to British Co- 

 lumbia, Connecticut, Pennsylvania, Colorado and Cali- 

 fornia. Illustrated in first edition as Sparganium simplex. July-Sept. 



11. Sparganium fluctuans (Morong) Rob- 

 inson. Floating Bur-reed. Fig. 171. 



Sparganium simplex fluitans Engelm. ; A. Gray Man. 



Ed. 5, 481. 1867. 

 Sparganium androcladum fluctuans Morong, Bull. 



Torrey Club 15: 78. 1888. 

 Sparganium fluctuans Robinson, Rhodora 7 : 60. 1905. 



Stem floating, slender, usually elongated ; leaves 

 rather narrow, 2"-5i" wide, slightly, if at all, 

 keeled, cellular-reticulate ; bracts much shorter 

 than the leaves, dilated and somewhat scarious- 

 margined near the base; inflorescence usually 

 branched, the main axis with 2-4 staminate heads, 

 the branches usually bearing 1 pistillate and 2 

 staminate heads; fruiting heads about 10" in 

 diameter ; nutlets brown, the body fusiform, some- 

 times constricted at the middle ; stigma obliquely 

 oblong. 



In ponds and cold lakes, Maine to Connecticut and 

 Minnesota. July-Sept. 



12. Sparganium hyperboreum Laest. 

 Northern Bur-reed. Fig. 172. 



Sparganium natans submuticum Hartm. Handb. 

 Skand. Fl. ed. 4: 312. 1843. 



Sparganium hyperboreum Laest. ; Beurl. Oefvers. 

 Vet. Akad. Foerh. 9: 192. 1852. 



Stem floating and elongated, or decumbent, or 

 ascending and 4'S' high ; leaves light green, very 

 narrow, i"-2" wide, flat or slightly round-keeled 

 near the base, in the case of floating plants some- 

 times greatly elongated ; leaf -sheaths slightly di- 

 lated near the base, but not scarious-margined ; 

 pistillate heads 2-4, the lower 1 or 2 usually 

 peduncled and supra-axillary; fruiting heads 

 4"-S" in diameter; nutlets dark-yellow, dull, the 

 body ellipsoid; stigma oval. 



In ponds and streams, Greenland to Newfound- 

 land, Hudson Bay and Alaska Also in northern 

 Europe and Asia. July-Sept. 



