274 GRASSES OF IOWA. 



Common in eastern Iowa, especially along the Mississippi river. It 

 forms floating islands in slow-moving and sluggish lakes and ponds. 



DISTRIBUTION. 



Iowa. 761 Armstrong (Pammel and Cratty) ; 669 Gilbert 

 (Combs and Ball) ; Ames (Crozier) ; Wilton (Hitchcock) ; Ames 

 (Hitchcock); Mt. Pleasant (Mills); 1048 Armstrong (Cratty) ; 

 Muscatine 1301 (Reppert) ; 968 Story City (Pammel and Stewart) ; 

 Ames 669 (Ball and Combs) ; Hamilton County (P. H. Rolfs) ; John- 

 son County, Armstrong (Cratty). 



North America. Wet places, often in running water, Newfound- 

 land to Alaska, south to New York (Parry), District of Columbia 

 ( Washington, Vasey), Ohio (Worthington, Horr), North Carolina, 

 Tennessee, Texas and California (Yosemite, Bolander), Montana (J. 

 Craig), Illinois (Lake View, Pammel). 



General. Europe, Great Britain, Germany, etc., to Siberia to the 

 Himalayas to northern Africa and Australia. Cosmopolitan. 



4. GLYCERIA BOREALIS. 



Glyceria borealis Pammel Nov. Comb. 



Glyceria fluitans var. angustata Vasey . Proc. Port. Soc. Nat. Hist. 2: 

 91. 1895. 



Panicularia borealis Nash. Bull. Torr. Bot. Club. 24: 348. 1897. 

 Britton and Brown. 111. Fl. 3: 505. /. 491a. 1898. 



DESCRIPTION. 



Slender Manna Grass. Culms erect from a creeping base, i| 

 to 5 feet (4.5-15 dm.) tall; sheaths generally longer than the internodes, 

 almost closed, the uppermost one enclosing the base of the panicle; 

 leaves linear, acuminate, 2 to 4 inches (6-12.5 cm.) long, 2 to 2\ lines 

 (4-5 mm.) wide; panicle slender, the exserted portion 1 to 1^ feet (3- 

 4 dm.) long, its branches appressed or nearly so; spikelets compressed- 

 cylindric, 1 to \\ inches (2-2.8 cm.) long, seven to twelve-flowered; 

 empty scales one-nerved, flowering scales scabrous all over, seven-nerved, 

 about i\ lines (5 mm.) long, the obtuse apex obscurely and irregularly 

 few-toothed; palet about 6 mm. long, acuminate, a little exceeding the 

 July to September. See figure 191, on page 276. 



