ON AQUATIC PLANTS. 



923 



like quicksilver. Height 4ft. to 6ft. The genus Nelumbium 

 embraces only two species, but specific names have been given 

 to several varieties of N. speciosum, the only distinction being 

 in the colour of their 



flowers, which range %ff&. 



from white and pale 

 rose to deep rosy- 

 pink, and in some 

 instances there are a 

 greater number of 

 petals which impart 

 a semi-double appear- 

 ance. 



Neptunia plena 

 (Water Sensitive 

 Plant) is a curiously 

 interesting subject 

 with long, spongy, 

 floating stems, bearing 

 bi-pinnate leaves con- 

 sisting of numerous 

 small leaflets of a pale- 

 green colour, which 

 are irritable, as in 

 those of the well- 

 known Sensitive Plant, 

 Mimosa pudica. The 

 flowers are small, pale 

 yellow, and arranged 

 in globular heads on 

 rather long peduncles, 

 which are produced 

 from the axils of the 

 leaves. 



Fig. 611. — Nelumbium luteum. 



Ottelia ovalifolia is a compact and interesting Aquatic, 

 with oblong-ovate leaves, some of which are submerged, others 

 floating on longer petioles. The flowers are borne above the 

 surface of the water in a solitary spathe, the three large inner 

 segments being of a pale yellow colour. 



Philydrum lanuginosum. — A monotypic genus, the species 

 being perhaps more interesting than beautiful. It is of biennial 

 duration and of erect habit of growth, its lanceolate leaves 

 being densely covered with woolly hair. The flowers are clear 

 yellow, and are borne on long spikes. Height 2ft. to 3ft. 



Pistia stratiotes (Water Lettuce). — A monotypic genus of 

 the Aroid family. The species is a very handsome floating 



