HIGHER PLANTS 



Giant bur-reed, Sparganium eurycarpum. — Giant bur-reeds 

 (Fig. 6i) grow along pond and stream borders among water 

 plantains, arrowheads, and pickerel-weeds. They are from 3 

 to 6 feet high v;ith very long ribbon-like leaves, about three- 

 quarters of an inch wide. The fluffy balls of their staminate 

 flowers are borne above the larger pistillate heads. The 

 fruits are green spheres of wedge-shaped nutlets packed close- 

 ly together like the sections of a pineapple. 



Occurrence. — In shallow water or on the shore, especially 

 in the larger marshes. Common. Blooms early June-late 

 July. United States, less frequent near Atlantic coast, rare 

 and local in Connecticut. 



Branching bur-reed, Sparganium americanum. — The plants 

 are similar to the giant bur-reed, but much more slender and 

 only I to 2 feet high (Fig. 61). The flower stems are more 

 or less branching but unbranched forms are often found in 

 the same colony with the others. 



Occurrence. — Common in many bogs, borders of ponds and 

 streams. Blooms June-August. Eastern states, south to 

 Florida, west to Minnesota. 



Animal associates. — Larvae of the leaf-beetle, Donacia, feed 

 upon its submerged roots (p. 280). 



Pondweeds — NajadacecB 



The pondweeds are probably more important to the wel- 

 fare of water animals than any other group, of aquatic seed- 

 plants. There are about forty North American species and 

 nearly every one of them flourishes in great numbers, provid- 

 ing either food or shelter for animals. They grow rooted to 

 the bottom and their long shifting leaves fill acres of pond 

 and lake water. Most of them are wholly submerged, except 

 for their flowers; in a few, like P otamogeton fiatans (Fig. 62), 

 the uppermost leaves float on the surface. 



Animal associates. — In Lake George, N. Y., pondweeds are 

 known to the local fishermen as "weeds" and the "weed" 



73 



