46 



AQUATIC PLANTS 



appear and become too large for the aquarium the plant had best be 

 removed. The Southern Spatterdock, Nuphar sagittcefolia, does not 

 develop aerial leaves, but they gradually lengthen as the warm season 

 progresses. The illustration shows the plant in March. Later the stems 

 and leaves will be longer. In October a new growth starts close to the 

 thick, running root or rhizome. The leaves of this Spatterdock are of 

 the brightest green hue and do not darken in strong light. Where the 

 rhizomes, or thick runners, have been broken off they have a tendency to 

 rot, eventually killing the plant. This seems to be overcome by planting 

 in good soil. 



Fig. 29. Japanese Spatterdock (Half she) 



The Japanese Spatterdock, Alisma spec, has leaves of a considerably 

 darker sage green, broader at the base. It is a continuous grower, has no 

 aerial leaves and multiplies readily at the rhizome. Altogether a satis- 

 factory plant for the large aquarium. 



QUILLWORT 



Isoetes is a widely distributed genus of a number of species. It is 

 found in the mud and sand at the edges of streams and ponds. In size 

 it varies from a few inches to several feet. The small submerged species 

 are worth trying in the aquarium, as they are tenacious of life. The leaves 



