97 



about J- inch wide on dilated petioles; submersed leaves narrowly 

 linear, about 1 inch long. Submersed flowers one or two on very 

 short peduncles. Emerged spikes \ to \ inch long, on pedunclesof 

 about the same length. Embryo coiled If times. 

 2435. P. fltjitans, Roth. 

 P. lonchites. Tuck. 



Common in running streams. Floating leaves long-elliptical, 3 6 

 inches long, acute, long-petioled, 17 23-nerved Submersed 

 leaves very long, sometimes 12 inches by 1 wide, lanceolate and 

 lance-linear, 7 1 5 nerved. Coarsely netted. Peduncles some- 

 what thickened upwards; spike cylindrical, fruit obliquely obovate, 

 3-keeled. the middle keel winged above. A form with remarkably 

 long stipules and leaves is found at Hull. Whole plant frequently 

 ruddy in colour. P. rufescens, Schrad, which has not yet been 

 found here has lenticular fruit, short-petioled floating leaves, 

 and the lower submersed leaves sessile. 

 2430. P. amplifolius, Tuck. 



Not uncommon. The Ottawa River at Aylmer, Little Chaudiere 

 and East Templeton. Kingsmere and Meech's Lake. A large 

 foliaceous and beautiful species ; submersed leaves lanceolate or 

 oval on short petioles with the tips recurved and undulate at the 

 edges, sometimes 7 inches long by 2 wide. Peduncles thickened 

 upwards. Fruit large obovate, 3-keeled with a broad stout beak. 

 Nutlet not impressed on the sides ; embryo slightly incurved. 

 2437. P. iieteropiivu-us, Schreb. 



/'. gramineus, L. var. heterophyllus, Fries 



Common and very variable according to the place where it grows. 

 Stem slender, compressed, much branched below ; floating leaves 

 mostly thin, variable, rounded or sloping at the base, but with 

 a short blunt point, 10 18-nerved, usually 1 2 inches long by 

 .', to | inch wide; submersed leaves linear-lanceolate, 7-nerved on 

 i he stem ; 3-nerved on the branches ; stipules obtuse, loose. Spike 

 \ l\ inches long, fruiting 'freely. When growing on mud. some- 

 times with only broad coriaceous leaves. 



var. GRAMINIFOLIUS, (Fries) Morong. 



The flaccid submersed leaves are very loug 2 5 iuches by 1 3 



