AQUATIC PLANTS OF FRESHWATER 



it has taken the place of Watercress. It should be introduced in loose 

 bunches as it requires strong light to grow submerged and makes a good 

 screen for the fishes. The dark-green, almost circular leaves with their 

 straight stalks strive to reach the surface and give a vigorous thriving 

 appearance to the plant, in fine contrast with the languid appearance of 

 the usual aquatic plants in the aquarium. 



CALLITRICHE 



The Water Starwort family contains a number ot 

 herbaceous aquatic and semi-aquatic species, with 

 slender stems, opposite spatulate leaves and minute 

 axillary flowers, of which the following are native 

 American species : — Callitriche verna or C. palustris. 

 Vernal or Spring Water-Starwort, Water Fennel; Fig. 

 130, C. bifida. Autumnal or Northern Water-star- 

 wort; C. heterophyllum. Larger Water-starwort and 

 C. austenii, Terrestial Water-starwort. They are 

 pond or basin plants but generally will not thrive in the 

 aquarium. 



Callitriche verna{l-And\.){s probably the hardiest, from 

 the aquariist's point of view, and is the most common and 

 generally distributed species in cold or running water 

 throughout the United States and Canada. It grows in 

 the mud with elongated one-nerved spatulate submerged 

 leaves and most peculiar floating leaves; which, though a 

 moderate distance from each other are arranged to form 

 a rosette, as the stalks of the lower leaves are longer than 

 those near the apex and bring the floating leaves into 

 clusters of 4's, 6's and 8's. The srpall axillary flowers reach 

 above the surface of the water and bloom from July to 

 September. Native or wherever introduced, it spreads 

 so rapidly as to become a nuisance, and should not be 

 used in lily-ponds. Water Starwort is introduced into the 

 ^°CauItM^crZ ^qii^rium in small bunches, but either so or floating on 

 the surface is eagerly eaten by goldfishes. 



FIG. 13 

 starwort. 



Reduced one-third. 



UTRICULARIA 



The Bladderworts are divided into aquatic and marsh species, floating 

 free or rooted in the mud. The aquatic species have finely divided leaves 

 covered with minute bladders, the marsh species rootlets under ground 

 and bladder-bearing leaves. There are about 150 widely distributed 



Z04 



