RARE OR INTERESTING PLANTS IN MICHIGAN. 



BY O. A. FARWELL. 



POLYPODIACE^. 



FiLix cRisTATA (Lin.) Farwell var. Clintoniana (D. C. E.) Farwell. 



A rare fern. Only three stations are given for it by Beal in the 

 Michigan Flora. It is to be found in cool, moist woods near Utica. No. 

 4179, June 6, 1916. 



SPARGANIACE^. 



Sparganium simplex Hudson. 



Several species have been segregated from the S. simplex of our earlier 

 manuals. I have not seen anytliing answering to the S. simplex Hudson 

 as now understood. S. Americanum Nutt. and S. divers! folitnn Graebner 

 should replace the S. simplex of Beal's Michigan Flora. 



Sparganium Americanum, Nutt. 



4248, June 29, '16, Cass Lake; 812, Aug. 25, '90, Keweenaw County; 

 812a, July 24, '10, Rochester. 



Sparganium diversifolium Graebner. 



Borders of Cass Lake: No. 219, June 16, 1885. 



Sparganium diversifolium var. acaule (Beebe) F. & E. 



2106, Aug. 15, '09, Rochester; 219a, June 16, '85, Keweenaw; 4249, 

 June 29, 1916, Cass Lake. 



FLUVIALACEtE. 



Potamogeton Americanus C. & S. 



Said to be a rare species in Michigan. It is to be found in a slip at 

 the Great Engineering Works, at River Rouge. No. 4340, July 21, 1916. 



JUNCAGINACE^. 



Triglochin maritimum Lin. Sp. PI. I, 339, 1753. 



Triglochin maritimum Lin. var. .exangidare Reichenb. Ic. Fl. Germ. 

 VII, 28, t. Lii fig. 93, 1845. 



I9th Mich. Acad. Sci. Rept., 1917. 



