AQ,UATIC PLANTS. 



35 



blotch at the hase of each petal. They have been 

 compared to some species of Cakehortus. It has 

 developed very finely, producing a profusion of 

 flowers, in one of the mud beds in which the 

 Nelumbiums are grown at Kew. It is raised 

 easily from seeds. Native of South America. 

 AlUmacea. 



Salvinia natam. — This is an extremely pretty and 

 interesting small aquatic, which floats on the water, 



ovate in shape, and provided with a swoUen stalk. 

 The flowers are inconspicuous. It produces curiously 

 homed fruits, which are supposed to resemble the 

 Caltrops of ancient warfare. They are the Jesuit's 

 Nuts of Venice, and are called " Chataigne d'Eau " by 

 the French. This and other species are used for 

 food, the nuts being ground into flour. In cultiva- 

 tion, good seeds are not produced, and they require to 

 be imported in damp moss. It may be grown in a 



The Lattice Plant (Ouuirimdra /enesfralis). 



and can be grown in any small vessel with mud in 

 the bottom. The leaves are oval, bright green, 

 thickly set on the upper surface with warts and 

 bristles. There are numerous pill-like fruits on the 

 dissected leaves below the rhizome ; there are no 

 true roots, but these leaves resemble them, and serve 

 the same purpose. The plant is annual, and the mud 

 over which it grows must be preserved, as it contains 

 the spores which produce a new crop the next season. 

 It is figured in the Gardeners' Chronicle, vol. xv., 

 N.S., p. 466. Native of the South of Europe. 

 MarsileaeecB. 



Trapa natans (the Water-caltrops). — An interesting 

 annual with pretty rosettes of toothed leaves, broaiily- 



tub with soil in the bottom, and in warm water out 

 of doors it grows weU. The species above mentioned 

 is European. Others, as the two-homed T. bicornis, 

 the " Ling " of the Chinese, might be introduced. Il- 

 lustrated in The Garden, vol. xxiv., p. 557. Oiui. 

 gra/riea, 



Trianea = Limnobium. 



Vallisneria spiralis. — This is specialty suited for 

 small aquaria. It has long narrow grass-like leaves, 

 and is interesting by the curious manner of its 

 fertilisation, and by its conveniently showing inter- 

 cellular circulation under the microscope. It must 

 be submerged, and it grows with great facility, but 

 the male plant appears more delicate than the 



