MICHIGAN ACADEMY OF SCIENCE. 365 



leaves, usually uarrowed but occasionally rounded at base. Keweenaw Co.. 

 S^)t. 4, 1885, No. 352. 



/*. amphibium f. terrestra (Ley.ss.) S. F. Kluke. ( /'. amithihium var. 

 tcrrcstre Leyss. Fl. Hal. 391, 1761; P. amphibium var. crcctiim Kittel, 

 Tausclienb. 308, 1853 ; P. amphibium var. saUcifoUum Schur, Enum. PI. 

 Transs. 583, 1866). A terrestrial, decumbent to erect, strif?ose pubescent 

 variation. Algonac, Sept. 13, 1915, No. 3895; Detroit, Sept. 20, 1918, No. 5151. 



P. amphibium var. marginatum n. var. Differs from the typical form 

 of tlie species only in having a foliaceous border on tlie stipular sheaths. 

 Keweenaw Co., Sept. 4, 1885, No. 351. 



P. AMPHIBIUM vai'. MABOINATUM f. HARTWKIGHTII U. COUlb. ( /'. amphil)- 



iiDii var. Hartivrightii (A. Gr.) Bissell, Khodora IV 105, 1902). A terrestrial, 

 decumbent to erect, strigose pubescent variation. Belle Isle, Aug. 2, 1892, No. 

 351a; Lakeville, Sept. 2, 1901, No. 351b; Parliedale, July 30, 1914, No. 3812; 

 Bloomfield, June 29, 1918, No. 5002. 



/'. amphibium var. nutans Mx. (P. cocvincum Muhl. and var. aquaticum 

 Willd. /'. amphibium var. cocvincum (Muhl.) O. A. F. Aquatic; leaves ovate- 

 lanceolate, usually cordate ; plant glabrous. Belle Isle, Sept. 3, 1892, No. 

 352a. 



P. amphihium var. nutans f. emersum (Mx.) n. f. {P. amphibium var. 

 emcrsum Mx. Fl. Bor. Amer. I, 240, 1803; P. coccineum var. tcrrcstrc Willd. 

 Enum. I, 429, 1809; P. amphibium var. tcrrestre Torr. F.l N. Y. II, 149, 1843; 

 P. amphibium var. Muhlcnbcryii Meisn. in DC. Prodr. XIV, 116, 1856). An 

 erect, terrestrial, strigose pubescent form. Belle Isle, Oct. 19, 1893, No. 1452; 

 Grosse Isle, Aug. 14, 1909, No. 1452a. It has been said that the terrestrial 

 forms are but mere phases and may be found on the same rhizomes which 

 produce the aquatic plants. My experience shows that the terrestrial forms 

 are rather common in Michigan, while the acpiatics are infreiiuent. I have 

 never seen the two phases associated or even in close proximity to ea<'h other. 



Polyyonum. avicularc L. var. veyetmn Ledeb. Along roadsides in (lie 

 Bloomfield hills. Prostrate. Billington & Farwell, June 29, 1918, No. 4989. 

 Also in Detroit, where the plants were ascending or erect. 



BLITACEAE. 

 Chetuopodium album L. A common and variable weed throughout the 

 State. Ypsilanti, June 17, 1891, No. 1152 ; Detroit, July 16, 1892, No. 1152a ; 

 Keweenaw Co., June 26, 1895, No. n52b. The following varieties are also 

 distinguishable. 



