FLORA OF MICHIGAN. 145 



CIY. ALISMACE^E. WATER-PLANTAIN FAMILY. 



455. AL.ISMA, L. WATER-PLANTAIN. 



*1272. A. Plaiitago, L. Th. 



Shallow water. Common. 



456. SAGITTARIA, L. ARROW HEAD. 

 *1273. S. variabilis, Engelm. Th. 



Wet places. Occurs in many forms, the most marked of which are the following: 



* 1274. var. obtusa, Engelm. 

 *1275. var. latifolia, Engelm. 

 *1276. var. angustifolia, Engelm. 



*1277. S. heterophylla, Pursh. Th. 



Elk Rapids, Winch. Cat. ; Detroit, D. H.Campbell; Alma, Chas. A. Davis. 

 1278. var. rigida, Engelm. 



Fruitport, E. J. Hill, and in the Great Lakes. 



*1279. S. graminea, Michx. . S. 



Dr. A. B. Lyons; Park Lake, Clinton Co., Bailey. 



457. ECHIXODORUS, Richard. 



1280. E. parvulus, Engelm. 

 Dr. A. B. Lyons; Gray's Manual, 6th edition. 



CV. NAIADACE^. PONDWEED FAMILY. 



458. TRIGLOCHLNT, L. ARROW-GRASS. 



1281. T. palustre, L. Th. 



Marshes. Frequent. 



1282. T. maritima, L. 



Shores of Great Lakes; borders of deer licks in interior; Macomb Co.; 8. Mich., Wright Cat.; 

 Hubbardston; Petoskey. 



459. SCHEUCHZERIA, L. 



1283. S. palustris, L. 



Keweenaw Co., Farwell; S. W., Wright Cat.; Macomb Co., Cooley; Hnbbardston; Montcalm Co. 

 Infrequent. 



46O. POTAMOGETON, Tourn. PONDWEED. 

 *128i. P. iiatans, L. Th. 



Ponds. Frequent. 



* 1285. var. prolixus, Koch. 

 Common in deep water of lakes and rivers. 



1286. P. Pennsylvanicus, Cham. Th. 

 Ionia Co. ; Macomb Co., Dr. D. Cooley ; Fruitport, E. J. Hill; Keweenaw Co., F. 



1287. P. later alls, Morong. 

 Bear Lake, Van Buren Co., E. J. Hill. Rare. 



1288. P. Spirillus, Tuckerman. U. P. 

 " Lake Superior," Gray's Manual; Keweenaw Co., F. 



