384 THE STORY OF PLANT LIFE 



appendages bent inwards, few-flowered, the flower- 

 stalk being thread-like, pale-coloured, half as broad 

 and as long as the spathe, which is swollen above the 

 stalk, oblong to lance-shaped, the blade short. It is 

 open down one side, the flowers being borne on the 

 side of the spadix. The stamens and pistil are in 

 two vertical rows, a carpel and a stamen alternately. 

 A retinaculum occurs on the outer side of the spadix 

 next the carpel. The carpel has the midrib facing 

 outwards. There is a single ovule with two stalkless 

 stigmas. The stamens are made up of two half- 

 anthers, united by a small connective. The carpel 

 and stamen on the same level form the flower and 

 a retinaculum is its bract. The fruit, an achene, is 

 short, smooth, and finely furrowed, the seeds short, 

 shining black when ripe. 



The plant is submerged, 3 in. long. It flowers 

 from April to August, and is a herbaceous perennial. 

 In winter it hibernates like other aquatics. 



Pollination is peculiar and effected by the agency 

 of water. The flower is submerged. The pollen- 

 grains are long threads of the same specific gravity 

 as salt water and so able to remain at any level. 

 When discharged they float at any level. The 

 stigmas are very large, and the styles are long, hair- 

 like, projecting from the spathe to catch the pollen, 

 which has no extine. This is similar to the way in 

 which plants are pollinated by the wind. 



The achenes are dispersed by the agency of 

 water. 



