MICROSPERME^ 279 



usually regular with the parts in threes. The perianth 

 is in two rows and consists of three or six segments. 

 These may be all petaloid, or the outer three may be 

 smaller and sepaloid, overlapping or valvate in bud. 

 The tube is adherent to the ovary at the base in the 

 female flowers, but there is no tube in the males. 

 There are three to twelve stamens in the male flowers, 

 inserted on the base of the perianth-segments. They 

 are in whorls of one to five. Sometimes those in the 

 innermost whorl are functionless, or staminodes. 

 They are opposite the perianth-segments, when three 

 in number, or in several series if more numerous. 

 The anther-stalks are free or united below. The 

 anthers are adnate. In the male flowers there is a 

 rudimentary ovary. The perianth is superior and six- 

 partite in the female flowers. The staminodes may 

 sometimes be functional. The ovary is inferior, one- 

 celled, and has three parietal placentae, or is three- 

 to six-celled, with two to fifteen carpels. There are 

 three to six styles, which are two-fid, free or united 

 below. The stigmas are decurrent, entire or two-fid, 

 as many as the carpels. The ovules are numerous, 

 ascending, anatropous, erect or pendulous. The fruit 

 is small, berry-like, one- to six-celled, submerged, 

 opening irregularly, ripening under water. The seeds 

 are numerous and contain no endosperm. 



Honey is half-concealed. The plants reproduce 

 vegetatively by hibernacula. The fruits are dispersed 

 by the wind or water. 



The group includes the interesting type Vallisneria^ 



