68 NAIADACEAE. 
6. Potamogeton alpinus Balbis. Northern Pondweed. (Fig. 147.) 
Potamogeton alpinus Balbis, Mise. Bot. 13. 1804. 
Potamogeton rufescens Schrad.; Cham. Adn. FI. 
Ber. 4. 1815. 
Plant ofa ruddy tinge, stems simple or branch- 
ed, somewhat compressed. Floating leaves spat- 
ulate or oblanceolate, obtuse, many-nerved, taper- 
ing into petioles 1/-5’ long; submerged leaves 
semi-pellucid, the lowest sessile, the uppermost 
petioled, oblong-linear or linear-lanceolate, ob- 
tuse or rarely acute, narrowed at the base, 3/— 
12’ long, 2’/-9’’ wide, 7-17-nerved; stipules 
broad, faintly 2-carinate, obtuse or rarely acute; 
peduncles 2’-S’ long ; spikes 1/-14’ long; fruit 
obovoid, lenticular, reddish, 114 ’’ long,1’’ thick, 
3-keeled, the middle keel sharp, the face arched, 
beaked by the short recurved style; apex of 
the embryo pointing directly to the basal end. 
, In ponds, Nova Scotia to British Columbia, New 
= y Jersey and California. Also in Europe. July-Aug. 
7. Potamogeton lonchites Tuckerm. Long-leaved Pondweed. (Fig. 148.) 
Potamogeton fluitans Roth, Fl. Germ. 1:72. 1788? 
Potamogeton lonchites Tuckerm, Am. Journ, Sci. (II.) 
6: 226. 1848. 
Stem terete, much branched, 3°-6° long. Float- 
ing leaves rather thin, elliptic, pointed at both 
ends, 2’-6’ long, 6’’-14’’ wide, many-nerved, on 
petioles 2’-8’ in length; submerged leaves pellucid, 
4/-13/ long, 2’’-12’’ wide, rounded at the base or 
tapering into a petiole 1/-4’ long; stipules 1/-4’ 
long, acuminate, acute or obtuse, strongly or 
faintly 2-carinate; peduncles thickening upward, 
2/-3/ long; spikes cylindric, 1/2’ long; fruit about 
2’’ long, 1//-14”’ thick, obliquely obovoid,the face 
nearly straight, the back 3-keeled, the middle keel 
rounded or often with a projecting wing under the 
style, not impressed on the sides; embryo slightly 
incurved, apex pointing slightly inside of the base. 
In ponds and slow streams, New Brunswick to Wash- 
ington, south to Florida and California. July—Oct. 
Potamogeton lonchites Noveboracénsis Morong, Mem. Torr. Club, 3: Part 2, 20. 1893. 
Floating leaves thicker, 3'-5%s’ long, about 2’ wide, 20-24-nerved, abruptly pointed or obtuse at 
thefapex ; peduncles sometimes 4’-5' and spikes 3' long. Lakes of central New York. 
8. Potamogeton Faxoni Morong. 
Faxon’s Pondweed. (Fig. 149.) 
Potamogeton Faxoni Morong, Mem. Torr. Club, 3: 
Part 2, 22. 1893. 
Floating leaves numerous, mostly obovate or 
oblanceolate, blunt-pointed or obtuse at the 
apex, narrowed at the base, often strikingly 
like those of P. spathulaeformis, 2’-3%3’ long, 
8/’-12’’ wide, 13-17-nerved, on petioles 2’-6’ 
long; submerged leaves oblong-lanceolate, acute 
or sometimes obtuse, 3’-5’ long, 6’/-12’’ wide, 
5-13-nerved, often with an irregular areolation 
oneach side of the midrib, borne on petioles 
14/-2’ in length; peduncles slightly thicker than 
the stem, 2/-5’ long; spikes dense, 1/-2’ long; 
fruit not collected. 
Little Otter Creek and Lake Champlain, Ferris- 
burg, Vermont, 
