88 WILD FLOWERS 



199. Greater Bladderwort, Utricularia vulgaris y Butterwort 

 family. A fairly common submerged plant of pools, especially 

 on peaty soil: the leaves are very much divided into narrow, 

 hair-like segments ; some of the segments are replaced by little 

 bladders, which act as traps for small 

 water-animals, the dead bodies of 

 which are utilised by the plant as 

 food : the large yellow flowers are 

 produced in spikes above the water in 



, 199. Greater Bladderwort. 



200. Water-Thyme. 



Bummer, but the plant flowers only rarely : the Lesser Bladder- 

 wort has more slender leaves and small pale flowers. 



200. Water-Thyme, Elodea canademis, Water-thyme family. 

 The stems are long, slender, and submerged, with close whorls 

 of 3 narrow, blunt, olive-green leaves : the flowers, which are 

 rarely seen, are small, on slender stalks, and pale violet : the 

 plant is not a native, but since its introduction from America it 

 has spread enormously, and often seriously chokes ponds and 

 canals. 



