182 
TYPHACES. 
Typha latifolia L. Sp. Pl. ii, 971 (1753). 
River bank, Norway, June 22 (No. 1425), 
Sparganium eurycarpum Engelm. in Gray Man. ed. 2, 430 (1856). 
River banks: Thedford, June 16; Mullen, July 17 (No. 1339). 
LEMNACE. 
Lemna minor L. §p. PI. ii, 970 (1753). 
Common in pools along the rivers and in the lakes of Grant County: Thedford, 
June 14, etc. (No. 1257). 
Lemna perpusilla Torr. FI. N. Y. ii, 245 (1843). 
I took this for LZ. valdiviniana Philippi, as the fronds are more or less elongated and 
as only one nerve could be seen. But comparison with the specimens in the National 
Herbarium persuaded me that it was L. perpusilia. The former has much narrower 
and thicker fronds. This is new to the State of Nebraska. In a spring near Plum- 
mer Ford, August 29 (No. 1723). 
Lemna trisulca L. Sp. PI. ii, 970 (1753). 
Common in pools and lakes throughout: Thedford, June 21; west of Whitman, 
September 19 (No. 1397), 
Lemna gibba L. Sp. P1. ii, 970 (1753). 
The specimens collected are much smaller than the specimens in the National 
Herbarium, which, however, are all European. The lower surface of the fronds is 
also of a darker color. In pools near Dismal River, Plummer Ford, July 5 (No. 1503). 
Also new to Nebraska. 
Spirodela polyrrhiza (L.) Schleid, Linnwa, xiii, 392 (1839); Lemna polyrrhiza L. 
Sp. Pl. ii, 970 (1753). 
Rare, in pools with Lemna minor, June 14 (No. 1258), 
ALISMACES. 
Alisma plantago L. Sp. Pl. i, 342 (1753). 
In dry lakes, northeast of Whitman, July 29 to 31 (No. 1616), 
Sagittaria latifolia Willd. Sp. Pl. iv, 409 (1806). 
The typical form was growing in the edges of streams and lakes: Mullen, July 17 
(No, 1563). The form with narrower lobes, which has been called variety angustifolia, 
was growing in deeper water, outside of the typical form. Mullen, July 17 (No. 1562), 
Another form (marked on the label: Form C, by Jared G. Smith), with leaves about 
half as large as in the typical, was growing on sandy banks of the rivers. Forks of 
Dismal, July 12 (No. 1533), No, 1812 is a diminutive form of the same. Forks of 
Middle Loup, July 27. 
Sagittaria arifolia Nutt.; J.G.Smith, Ann. Rep. Mo. Bot. Gard. vi [reprint 6], pl.i 
(1894), 
The character that first arrested my attention was the bracts, which are lanceo- 
late and much longer than in S. latifolia. In streams: Forks of Middle Loup River, 
July 26; South Dismal River, August 14 (No. 1809). No. 1811 is a form having 
thinner, nearly membranaceous leaves with shorter lobes. Forks of Middle Loup 
River, July 27. 
. NAIADACES, 
Triglochin maritima L. Sp. Pl. i, 339 (1753), 
In a meadow, near Thedford, June 14 (No. 1280), 
Potamogeton natans L. Sp. Pl. i, 126 (1753). 
In lakes in Grant County: Swan Lake, August 7; northwest of Whitman, Septem- 
ber 19 (No. 1652). 
