A REVISION OF THE AMERICAN LEMNACEAE. 99 
Specimens examined from Ontario (Fowler, 1888); Maine (Fernald, 
1891); Vermont (Brown); Rhode Island (Thurber, 1846); Connecticut 
(Eaton; Eames, 1895); New York (Austin; Leggett, 1870, fertile); New 
Jersey (Parker, 1861); Pennsylvania (Thurber, 1848); Virginia (Vasey, 
1874); South Carolina (Ravenel, 1872); Florida (Curtiss, no. 4544, 1894; 
Nash, no. 2282, 1895); Michigan (Bigelow, 1865; Gillman, 1871); Wiscon- 
sin (Hale, 1861) ; Illinois (Hall, 1867; Schneck, 1893, resting fronds) ; Ten- 
nessee (Gattinger, 1882); Minnesota (Hale, 1861); Iowa (Fink, no. 398, 
1894); Missouri (Broadhead, 1864; Engelmann, 1867; Trelease, 1895; 
Widmann, 1895; Bush, no. 1583, 1892 and no. 797, 1896; Thompson, 1896) ; 
Arkansas (Engelmann, 1835); Louisiana (Dr. Hale, about 1830-40; Hil- 
gard, 1867); Nebraska (Webber, 1889; Rydberg, no. 1258, 1893); Kansas 
(Kellerman and Carleton, 1884; Norton, 1898; K. S. A.C., no. 533, 1895) ; 
Texas (Mex. Bound. Surv., no. 1412, 1855-56; Reverchon, no. 492, 1877); 
Utah (Jones, no. 5979, 1894); Nevada (Watson, no. 1126, 1867); Oregon 
(Hall, no. 498, 1871); California (Brewer, no. 2190, 1860-62; S. B. and 
W. F. Parish, no. 1100, in part, 1881; Rattan, no. 59, 1884). 
Lemna Linn. Sp. Plant. 970. 1753. 
Stipe attached to the basal margin of the frond. Repro- 
ductive pouches two, triangular, opening as clefts in either 
margin of the basal portion of the frond. Root solitary. 
Spadix of one pistillate and two staminate flowers, pro- 
duced in the vegetative reproduction pouches ; spathe vari- 
ous; filaments curving upward from the margin of the 
frond. Anthers bilocellate, dehiscing transversely. 
* Spathe sac-like; ovules amphitropous when solitary, anatropous 
when more than one; rootsheath long, cylindrical, unappendaged. 
+ Fronds sessile or very short stipitate, more or less wing-margined 
on either side of the base, subpeltately attached; fruit rounded lenticu- 
lar; rootcap bluntly rounded. 
++ Fronds pale and usually strongly gibbous beneath, green and 
brown mottled above; fruit winged with rounded lobes at the upper 
margin on either side of the stigma; seeds one or more, 
Lemna cispa Linn. Sp. Plant. 970. 1753. Telmatophace 
gibba Schleid, Linnaea 13: 391. 1839. 
Fronds solitary to four in a group, commonly two, or- 
bicular to obovate, 2-4 mm. wide by 2-5 mm. long, thick, 
description so admirably in all essential characters, I feel perfectly justi- 
fied in identifying the one with the other. 
9 
