378 THE STORY OF PLANT LIFE 



segments is higher on the axis than the outer stamens. 

 The flowers are wind-pollinated. Pollen collects in 

 the hollow bases of the perianth-segments just below 

 the stamens. It remains till wind disperses it. The 

 stigmas are brush-like. 



The carpels when ripe surround a central axis or 

 beak, and have long, sharp, spine-like lobes, which 

 catch in the coats of animals, which thus disperse 

 the fruits. 



There is no other common EngHsh name beyond 

 the one cited. 



There is a maritime species allied to the inland 

 one described. 



Triglochin palustre. — The illustration {Fig. 105) 

 shows the long, slender leaves and the slender scape, with 

 flowers in a raceme, and spinose fruits. 



Broad-leaved Pondweed (Potamogeton natans). 



In the first Latin name, derived from the Greek, 

 potamos, river, geiton, neighbour, the aquatic habit is 

 indicated, and the second Latin name refers to the 

 floating leaves. 



There appears to be some reason for regarding the 

 Pondweeds as originally derived from land plants. 

 In some the leaves are floating, in others the plant 

 is wholly submerged, whilst others may live almost 

 on land as P. heterophyllus, or in shallow pools as 

 P. polygonifolius. The one under description is near 

 the ancestral type, being least modified to aquatic 

 conditions. 



