19 
to Oregon. (Plate XXIX., showing submerged leaves on the 
right.) 
6. POTAMOGETON ALPINUS, Balbis, Misc. Bot. p. 13 (1804). 
P. rufescens, Schrad. ap. Cham. Ad. Fl. Ber. p. 5 (1815). 
As an illustration of the confusing extent to which synonymy 
has been carried in this family of plants, Mr. Bennett enumerates 
(Jour. Bot. xxvii., 242) 21 names given to this species by differ- 
ent authors. 
Entire plant of a ruddy tinge, especially the leaves and 
spikes. This is very apparent in clear water. Stems simple or 
sparsely branched, somewhat compressed; internodes usually very 
long. Floating leaves coriaceous, spatulate or oblanceolate, obtuse, 
sloping into petioles 1-5 inches long, 17-21 nerved, mostly oppo- 
site, the midrib with a chain-like areolation on each side. Sub- 
merged leaves thin, semi-pellucid, the lowest sessile, the upper- 
most petioled, opposite under the branches and peduncles, oblong- 
linear or linear-lanceolate, obtuse or rarely acute, narrowing at 
base, 3-12 inches long and 2-9 lines wide, 7-17 nerved. Stipules 
broad, faintly bicarinate, with many fine nerves, pellucid on the 
edges, obtuse or very rarely acute. Peduncles about the thickness 
of the stem, 2-8 lines long, sometimes 3 or 4 or even more near the 
summit of the stem. Spikes cylindrical, 1-1% inches in length, 
densely fruited, occasionally appearing compound. Fruit obovate, 
lenticular, smooth, reddish in color, about I 14 lines long by 1 line 
wide, 3-keeled, middle keel sharp, almost winged, sloping on each 
side into obscure lateral keels; face arched and beaked by a short 
recurved style; apex of the embryo pointing directly to the basal 
end. It is stated by Dr. Robbins in Gray's Man. Ed. 5, that the 
fruit is “pitted when immature." In mature fruit no pit is seen. 
The nutlet shows smooth even sides, with a shallow depression 
near the base of the facial edge, and two obscure furrows on the 
back. This species, though common in Europe, while widely dif- 
fused is rare in our country. 
Greenland; Canada from Nova Scotia to Vancouver's Island 
(Macoun); near Fort Yukon, Alaska (Kennicot); St. John's River, 
Maine (Pringle); Barnet, Vt. (Dr. Blanchard); Brattleboro, Vt. 
(Frost); Lake Champlain, on the Vermont and New York sides 
(Faxon, Morong); State line, Western Massachusetts (Robbins); 
