52 
15. POTAMOGETON PRAELONGUS, Wulf. in Rom. Arch. iii. 331 
1805). 
P. flexuosus, Schleich. and Wredow, Meklenb. Fl. (1807). 
P. flexicaulis, Dethard, in Strelitz. Anz. 1809. n. 50. 
Stem white, flexuous, flattened, much branched, growing in 
deep water, sometimes 6 to 8 feet in length. Leaves all sub- 
merged, oblong or oblong-lanceolate, obtuse and cucullate at the 
apex, splitting on pressure, semi-amplexicaul, of a bright green 
‘color. They are from 2 to 12 inches in length, and from % to 
114 inches wide, with only 3 or 5 main and from 7 to 17 finer 
nerves, sometimes with a narrow reticulated space on each side of 
the midrib. Stipules white, scarious, obtuse and commonly 
closely embracing the stem. Abnormal specimens with spread- 
ing stipules 2-3 inches long have been collected in Maine by Miss 
Kate Furbish. Peduncles from 3 to 15 inches and occasionally 
as much as 20 inches long, erect, straight, about as thick as the 
stem, and often very numerous. Spikes 1-2 inches long, thick, 
cylindrical, densely fruiting. Fruit dark green, obliquely obovate, 
2-2% lines long and 177-2 lines wide; the back much rounded, 
often with the upper curve nearly as high as the style. Middle 
keel sharp and prominent, sloping on the sides to rather obscure 
lateral keels; face straight or nearly so; style short, obtuse, facial; 
apex of embryo pointing directly to the base. 
This species fruits in our country in June and July, and usually 
withdraws its stems beneath the water as soon as the fruit is set. 
Hence the difficulty of obtaining good fruit unless dredging is 
resorted to. 
Deep water, lakes and ponds, Nova Scotia, New Brunswick, 
Ontario and Vancouver's Island (Macoun’s Cat.); Shelburne Pond 
Vt. (Pringle); Wenham and Fresh Ponds, Mass. (Morong); Bantam 
Lake, Litchfield, Conn. (Morong); Lake Salstontall, Conn. (Prof. J. 
A. Allen); Canaan, Conn. (Robbins); Budd's Lake, N. J. (Porter); 
Lake Canandaigua, N. Y. (Morong); Maltowah Lake and Chen- 
ango River, N. Y. (Coville); Frankfort, Mich. (Hill); along the 
Great Lakes to Lake Superior (Robbins); Vermilion Lake, Minn. 
(L. H. Bailey); Iowa (Arthur's Cat.; National Park (Clifford 
Richardson); Sierra Co., Cal. (Brew. and Wats. Bot. Cal) (Plate 
XXXIX.) . 
