59 
Var. GRACILIS, Morong, Bot. Gaz. 10, 255 (1885). 
Internodes 1-3 inches in length, with a few teeth near the 
upper part. Leaves scarcely М line wide, with 15 to 24 large 
teeth on the margins and few dorsal teeth ; sheaths with 2-3 teeth 
on each margin; seeds hardly 2 lines long and sculptured with 
about 25 rows of nearly square or irregularly oblong reticulations. 
The whole plant, at least when dry, purple tinged. 
Florida (A. H. Curtiss, No. 2705). A form very nearly, if not 
quite this, was collected by Prof. Wm. R. Dudley off Canoga 
marshes, New York (Cayuga Flora, p. 104). 
Var. RECURVATA, Dudley, Cay. Fl. 104 (1886). 
Stems dichotomously branched, the branches and leaves re- 
curved. Leaves 3-6 lines long, narrow, with 2-4 large teeth on 
each margin longer than their breadth, without dorsal teeth; inter- 
nodes short, naked, or with I or 2 teeth; sheaths ı-toothed on 
each side. 
Black Lake, Cayuga Marshes, New York (Dudley). 
The species rare in North America. Canoga Marshes and 
Cayuga Lake, N. Y. (Morong, Dudley); Florida (Chap. Fl.); 
Utah (Parry); Lower California (Palmer.) Attributed by Watson 
in Bot. Cal. to Clear Lake (Bolander) and Huntington Valley, 
Nevada (Wheeler). Cuba. Occurs in Europe and Asia. (Plate 
LXV.) 
2. Nars FLEXILIS (Willd.) Rostk. and Schmidt. Fl. Sed. 384 
(1824). 
Caulinia flexilis, Willd, in Act. Ac. Berol. 89 (1798). 
Naias Canadensis, Mx. Fl. ii. 220 (1803). 
Stems slender, dichotomously much branched. Leaves linear, 
pellucid, acuminate or abruptly acute, 14-1 inch long by %-1 line 
wide, numerous and crowded on the upper part of the branches, 
with 25-30 minute I-celled teeth on each edge; sheaths obliquely 
rounded, with 5-10 teeth on each edge. Dicecious. Fruit ellip- 
soidal, with very thin pericarp, 1-13% lines long and Y-% of a line 
in diameter; style long, divided into 3 short stigmas, persistent; 
seeds smooth, shining, sculptured, sometimes quite faintly, with 
30-40 rows of squarish or hexagonal reticulations which are 
scarcely seen through the pericarp. The seeds are generally 
