THALAMIFLOR^ 147 



Tamarix gallica. — The heath-like habit of the 

 Tamarisk is shown in Fig. 27, as well as the catkin-like 

 character of the inflorescence. 



14. The Water-Wort Group. 



The Order Elatinaceae, like the last, is not an 

 extensive group, consisting of thirty species, with 

 two genera. There are two British species, both 

 rare. They are found in the temperate and tropical 

 regions, and are aquatic plants. From the Pink 

 Group these plants are distinguished by possessing 

 a pin-headed stigma, a three- (or more) celled 

 capsule, and exalbuminous seeds. 



These plants are small, annual, aquatic, herbaceous 

 plants, or undershrubs. The aquatic types are 

 amphibious, and in this case become structurally 

 adapted to terrestrial conditions, as in the Lake- 

 weed. 



The stems are rooting. The leaves are opposite, 

 or in whorlsj entire or toothed, with very small 

 stipules. 



The flowers are exceedingly small, solitary and 

 axillary, or borne in dichasial cymes. They are 

 regular, hermaphrodite, with parts in twos or more 

 up to six. The calyx is hypogynous, and either free 

 or united at the base, with three to five sepals. The 

 petals are entire, hypogynous, three to five, the 

 corolla imbricate in bud. There are two to five 

 stamens, or twice as many, in two whorls, but the 



