THE FEOGBIT FAMILY. 405 



The beautiful Limnocharis Humboldtii of California, not infrequent in green- 

 houses where aquatics are cultivated, floiu-ishes in the same reservoir as the 

 water arrow-leaf, encouraged by the kindly action of the warmth from the engine- 

 house. 



CXXXIV.— THE FROGBIT FAMILY. Hydrocharidea. 



Beautiful aquatics, the flowers unisexual, enclosed in a peculisir 

 sheath-like cover called a " spathe," and going through all the stages 

 of their existence below the surface of the water, except at the period 

 of the fertilization of the pistil, when they are raised into the air for 

 a few hours. Sepals three ; petals three, sometimes absent ; stamens 

 usually numerous, and seated, along with the perianth, on the summit 

 of the ovary. There appear to be about twenty species, the fresh 

 waters of Europe, North America, Egypt, the East Indies, and New 

 Holland containing the greater part, while a few grow in estuaries of 

 the sea. 



Two are natives of Britain, and both grow wild, or as colonists, near 

 Manchester. 



1. Leaves sword-shaped, six to twelve inches long, succulent, acute, with a 



prominent midrib, and pungent marginal prickles, and growing in dense, 

 erect, aloe-like tufts upon the surface of the water, to which they are 

 thrown up from creeping runners that penetrate far into the mud. 

 Flower-stalk from the centre of the tuft, four to six inches long, flattened 

 and two-edged, and supporting a spathe formed of two bracts about an 

 inch in length, inside of which are several large, white, and peduncled 

 male flowers, and a solitary and sessile female. The former have twelve 

 to twenty stamens; the latter has six pistils. The flowers are some- 

 times imperfectly dioecious, and sometimes bisexual Water Soldiee. 



2. Stems slender and floating ; at inten'als bearing tufts of kidney-shaped or 



circular leaves, one and a half to two inches across, purplish underneath, 

 petiolate, smooth, and fleshy, and which lie flat upon the surface of the 

 water, with abundance of long and thick white rootlets descending at the 

 same places. Flowers in small umbels from the bosom of the leaves, nearly 

 an inch across, white, except the centre, which is yellow; the males two 

 or three together, with three to twelve stamens ; the females on separate 

 plants, with six styles and two-cleft stigmas, the peduncles of both sur- 

 rounded by membranous and pellucid spathes Frogbit. 



H.VBITATS AND LOCALITIES. 

 1. Water Soldiek — [Stratiotes aloides.) 

 Ponds, lakes, and meres, not uncommon. Abundant in Radnor 

 Mere, Alderley Park, and in the sheet of water in Spring Wood, 



