304 A GUIDE TO THE WILD FLOWERS 



oval, or oblong-oval, pointed rather abruptly at the tip, 

 slightly heart-shaped at the base. Flowers in a small close 

 spike, greenish_and inconspicuous, which stands above the 

 surface aSouFan inch when the nut-like tiny fruits are ripe. 

 Throughout North America, Europe and Asia, in ponds and 

 slow moving streams. Fig. 930. This, the next two, and Nos. 

 936 and 940, are merely representatives of many species of 

 Pondweeds. 



931. PoNDWEED. Potamogeton cpihydrus. (Zannichelliaccac.) 

 Somewhat resembling No. 930, but the submerged leaves 

 about y^ in. wide and obviously with a net-work arrange- 

 ment of veins along the main vein, while the floating leaves 

 are more oblong and blunt. In ponds and slow streams. Nova 

 Scotia to Penn. and So. Carolina. 



932. Large-leaved Pondweed. Potamogeton amplifolius. 

 (Zannichelliaceae.) The coarsest and largest of all our Pond- 

 weeds. Submerged leaves, large, oval, or oblong-oval, stalked, 

 often bent sickle-fashion, 3^-7 in. long. Floating leaves, 

 many veined, oval, abruptly pointed, rounded at the base. 

 In ponds and lakes. Ontario to Conn., Kentucky and west- 

 ward. Fig. 932. 



933. Leaves wholly submerged. 



Submerged leaves slender- tape-like or thread-like 

 Flowers wholly submerged 



Leaves tape-like, often 2-4 ft. long Eel-grass no. 934 



Leaves not tape-like, either long and thread-like or short 

 and narrow 



Leaves opposite or alternate 

 Leaves l4-i in. long ; flowers and fruits solitary at the 



leaf joints Water-fennel no. 935 



Leaves 1-2 in. long; flowers and fruits in small, stalked 



clusters Leafy Pondweed no. 936 



Leaves in clusters of 3 or more 

 Leaves H-'jA in. long, undivided . . Water-weed no. 937 



Leaves J^-i l4 in. long, forked Hornwort no. 938 



Flowers, or some of them, on stalks above the surface 



Water Milfoil no. 939 



Submerged leaves cup-like, the stem passing through them 



Pondweed no. 940 



