302 A GUIDE TO THE WILD FLOWERS 



Then the spiral stalk uncoils, the tiny flower comes to the 

 surface ready for the perfectly timecTirrght of the male 

 flowers from the depths. These, by an ingenious buoyancy 

 are suddenly released, and after reaching the female flower 

 and fertilizing it, are carried off down stream to die. The 

 female flower, already a mother, slowly coils up its long stem, 

 and down near the bottom ripens the seed resulting from this 

 marvellously timed operation. 



The aquatic plants below are in many families. A great 

 many more are known in the area than can be admitted here. 

 Those treated may be divided into two main groups 

 thus : 

 Flowers on or above the surface, relatively showy, always ob- 

 vious and colored no. 944 



Flowers either submerged, or if above the surface, small, incon- 

 spicuous, and not brightly colored 

 Plants of salt water, or in brackish bays or inlets near the sea 



no. 941 



Plants of fresh water 



Leaves wholly submerged no. 933 



Some or all the leaves floating 



Plant without a true stem, merely floating free on the 



water, often in masses Duckweed no. 927 



Plants with a true, often mostly submerged stem 

 Leaves above or on the surface, scarcely Yio in. wide 



Floating leaves sharply toothed or cut 



Mermaid-weed no. 928 



Floating leaves not toothed 



Carolina Water-shield no. 929 



Leaves above or on the surface ; oval or lance-oval, at 

 least I in. wide 

 Submerged leaves narrow, scarcely ^ in. wide 



Submerged leaves thread-like 



Common Pondweed no. 930 



Submerged leaves about % in. wide Pondweed no. 931 



Submerged leaves, broad, sickle-shaped 



Large-leaved Pondweed no. 932 



927 Duckweed. Lemna trisculca. (Lemnaceae.) A free float- 

 ing aquatic with no apparent stem, and with two tiny joined 

 leaf-like structures from which is suspended a single tiny 

 root, not over %. in. long. The leaf-like floating structures are 

 generally oval, about % in. long. Flowers almost microscopic. 



