1922] 



PFEIFFER — MONOGRAPH OF THE ISOETACEAE 141 



Howell (Mo. Bot. Gard. Herb, and U. S. Nat. Herb.) ; The 

 Dalles of the Columbia, 11 October, 1881, Pringle (Mo. Bot. 

 Gard. Herb, and U. S. Nat. Herb.) ; Hood River, May, 1882, 

 T. J. Howell (N. Y. Bot. Gard. Herb.) ; The Dalles, in small 

 ponds. 20 May, 1882, T. J. Howell (Mo. Bot. Gard. Herb.) ; 

 shallow pond 14 miles below The Dalles, 21 May, 1882, T. J. 

 Howell (Mo. Bot. Gard. Herb.) ; nearly submerged in small 

 ponds, Hood River, 22 May, 1882, T. J. Howell (Mo. Bot. 

 Gard. Herb, and U. S. Nat. Herb.) ; Hood River, 3 July, 

 1891, T. J. Howell 1521 (Mo. Bot. Gard. Herb., U. S. Nat. 

 Herb., and Univ. Minn. Herb.) ; in small ponds at The 

 Dalles, May, 1895, T. J. Howell 698 (Mo. Bot. Gard. Herb.) ; 

 near Dalles City, 4 May, 1898, Suksdorf 2617 (Mo. Bot. 

 Gard. Herb.); in or near shallow water near Dalles City, 

 Wasco Co., 7 June, 1904, Suksdorf 6/+2 (Mo. Bot. Gard. 

 Herb.) ; shallow water on shore of Rogue River, near Soli- 

 tude Bar, 26 June, 1917, Nelson 1531 (Gray Herb.); com- 

 pletely submerged in standing water along S. P. tracks, 3 



mi. south of Salem, 27 June, 1921, Nelson 3939 (Mo. Bot. 

 Gard. Herb.) ; bottom of dried-up pool, along S. P. tracks, 

 3 mi. south of Salem, 16 July, 1921, Nelson 4059 (Mo. Bot. 

 Gard. Herb.). 



California: in shallow water, gravel, submerged, growing singly, 



Bear Valley, San Bernardino Mt., alt. 7000 ft., August, 1882, 

 S. B. & W. F. Parish 1440 (Mo. Bot. Gard. Herb, and U. S. 

 Nat. Herb.); in dry beds of shallow ponds, Olema, June, 

 1886, Curran (Mo. Bot. Gard. Herb.); Priest Valley, Mont- 

 erey Co., 13 May, 1893, Miss Eastwood (Mo. Bot. Gard. 

 Herb.) ; El Cajon, April, 1895, Brandegee (Mo. Bot. Gard. 

 Herb.) ; on sand meadow, elev. 9000 ft., south fork Kaweah 

 River, Tularo Co., 1 August, 1895. Dudley 1043 (Dudley 

 Herb.) ; in a pond, near Hyampom, Trinity Co., 10 June, 

 1896, Howe & Blasdale (Mo. Bot. Gard. Herb.); growing 

 wholly or partially submerged in pond near Hyampom, 

 Trinity Co., 10 June, 1896, Howe (N. Y. Bot. Gard. Herb.) ; 

 in a marsh about a mile from Olema, Marin Co., 4 July, 1896, 

 Miss Eastwood (Mo. Bot. Gard. Herb., Gray Herb., U. S. 

 Nat. Herb., Univ. Minn. Herb.) ; pools in the plains, Chap- 

 man's, Mariposa Co., 27 April, 1897, Congdon 91 (Gray 

 Herb.); Powder Mill Canyon, Santa Cruz, 25 May, 1900, 



