ON AQUATIC PLANTS. 



889 



sheltered situation should be selected, and the crowns of the 

 plants Submerged sufficiently deep in the water to prevent them 

 from becoming frozen. Although the first severe frost will cut 

 the plants down, they will nevertheless restart into growth in the 

 spring. 



Sagittaria sagittifolia (Common Arrow-head) (Fig. 595). — 

 This well-known British plant, with its handsome sagittate leaves, 

 and scapes of showy white flowers, is a very desirable subject 

 for the water-garden ; height about 2ft. S. s. flore-pleno is less 

 vigorous in habit than the type, but . has handsome double 

 white flowers ; height about i-|ft. 



FIG. 594. — PONTEDERIA C0B.DATA. 



Scirpus lacustris (Common Bulrush). — This' vigorous-growing 

 British plant has tall cylindrical tapering stems which produce 

 a very striking effect. Height about 6ft. 



Typha " angustifolia (Lesser Reed Mace) is an elegant tall- 

 growing British plant with long narrow leaves ; the long, 



