232 THE STORY OF PLANT LIFE 



outer whorl opposite the petals, with very short 

 anther-stalks. The stamens are long, except in the 

 Starworts, four-angled, with lateral slits. 



There is either no disc or a very small one. 

 The ovary consists of two to four carpels, or one, 

 united below, and inferior. The styles (which are 

 distinct) and stigmas are of the same number as 

 the carpels. In the Starworts there are two. The 

 fruit consists of drupes or nuts, two- to four-celled, 

 indehiscent, or one to four, small, one-seeded. The 

 seeds are pendulous and solitary. 



The properties of the group are quite unimportant. 



In Mare's Tail the leaves are entire and in whorls 

 and the flowers are apetalous. In the Water Mil- 

 foils the leaves are all in whorls, or the lower ones 

 much divided, and there are two to four petals ; in the 

 Starworts the leaves are all opposite and entire, and 

 the flower has no perianth. 



Mare's Tail {Hipptcris vulgaris). 



The name Mare's Tail (a translation of the first 

 Latin name) is applied to the habit of the plant, 

 which is not unlike that of the Horsetails (plants 

 much lower in the scale, or Cryptogams), in which 

 the stem is clothed with whorls of slender branches, 

 which resemble a horse's tail. 



This is an aquatic plant, like the Horsetails, and 

 the reduction in the leaf-surface is an adaptation to 

 the aquatic habit. Really such slender leaves are 



