96 



tall plant with rush-like leaves and slender racemes (if small green 

 flowers which have much the general appearance of the fruiting 

 spikes of Plaiitago. 



SCHEUCHZERIA, L. 

 24'2G. S. palustris, L, 



Peat-bog. Rare Dominion Springs, Mer Bleue. June : 2. A 

 curious plant with creeping, jointed rootstocks. grassy leaves and 

 simple zig-zag stems terminated by a loose raceme of 5 or 6 

 flowers. 



POTAMOGETON, L. Pond-weed. 



2428. P. NATANS, L. 



Common in all waters. Floating leaves, all long-petioled, elliptical. 



coriaceous; submersed leaves (phyllodia) very narrow, grass-like 



Spikes all emerged, cylindrical, densely flowered; fruits fleshy and 



swollen. Nutlet impressed on the sides. 



var. prolixus, Koch. 



This is only a form found in deep or flowing water, more slender in 



all its parts. I have never found it in fruit here. 



2430. P. Pennsylvanicus, Cham 



P. Claytonii, Tuck. P. Nuttallii, Ch. and Sch. (Morong.) 



Very common. Steins compressed. Floating leaves nearly always 

 produced in large numbers, opposite. 1 3| inches long, 11 27 

 nerved, oblong, tapering into a short petiole. Easily recognized 

 by the numerous 2-ranked, linear, 5-nerved, submersed leaves the 

 lateral nerves nearly marginal, the central space between the 

 inner nerves coarsely cellular-reticulated and silvery. 



2431. P. Vaseyi, Robbins. 



A slender delicate species, rare. In the Rideau Canal between 

 Stewarton and the Exhibition Grounds, the very rare fruiting form 

 with floating leaves may occasionally be found. Floating leaves 

 obovate, 5-nerved, \ to - inch long, about the length of the filiform 

 petioles. Spikes emerged, 3 9 flowered, interrupted. Submersed 

 leaves thread-like, 1 1| inches long. 



2432. P. Spirillus, Tuck. 



Shallow water. Common in the Ottawa. Floating leaves generally 

 freely produced, oval to lanceolate, from i to ,' of an inch long, by 



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