24 (/) Plants submerged in water at all times, collapse when taken from the water 

 (flowering plants only, exclude algae); flowers may be above the water surface 

 and later withdrawn 



25 



24 (1) Plants may be submerged only periodically by tidal waters or completely terrestrial. . 27 



25 (24) Blade of leaf long, flattened, 1.5-6 mm 

 wide and up to a meter long; usually 



in very soft muddy bottom Zostera marina, 



Eel Grass 



Figure 26.— (a) Habit sketch; 



(b) terminal portion of leaf XI- 



25 (24-) Blades of the leaf, threadlike; in quieter water of estuaries, pools in the tidal 

 marsh, and brackish pools back of beaches 



26 



13 



