9 8 



HOUSE, GARDEN, AND FIELD 



FIG. 24. White water-lily. Section 

 of fruit , slightly reduced. An enlarged 

 seed is shown at the side. 



another ; each has a sloping buttress (Fig. 19). The 



underside (Fig. 20) is flattened, and bears fewer leaf-scars 



than the top or sides. The 

 rootlets spring as a rule 

 from the base of a leaf- 

 scar, three to six in a 

 longitudinal series ; when 

 they wither and fall off, 

 they leave pits (Fig. 20). 

 No ring of harder tissue 

 is seen on the cut end. 

 The rootstock does not 

 contain so much tannin as 

 that of Nymphaea. 



The flowers of Nymphaea 

 are formed beneath the 



surface of the water, and only float when expanded. Even 



when they have once expanded, they close every evening, 



beginning as early as 4 o'clock in 



the afternoon, and sink. There 



are four green sepals (or outer 



floral leaves) and probably only 



eight true petals, but the number 



is greatly increased by secondary 



petals (four groups of four each) 



which form within and between 



the four primary petals of the 



inner whorl. The secondary 



petals pass gradually into the 



stamens, and a narrow white 



petal often bears one or two 



anther - lobes. Very likely all 



the secondary petals were once 



stamens ; if so, the flower is a 



double one, like a cabbage rose. 



The unaltered stamens are very numerous. The pistil 



consists of many united carpels, each many-seeded, and 



FIG. 25. White water-lily. 

 Ovary, with two sepals. Slightly 

 reduced. 



