1974 



A TEXTBOOK OF THEORETICAL BOTANY 



and large terminal spikes or racemes. The flowers are hermaphrodite, 

 consisting of two whorls of petaloid segments followed by six stamens 

 arranged in two whorls and two trimerous whorls of free or united carpels 

 of which the outer three are sterile. The fertile carpels contain one or two 

 anatropous ovules. A double whorl of carpels is a very rare occurrence in 

 the Angiosperms. The flowers are anemophilous and protogynous. The 

 most important genus is Triglochin which is distributed in temperate 

 regions of both the New and the Old World. In Britain there are two species, 

 T. pahistre which is found in marshy meadows and T. maritimum (Fig. 1904) 



Fig. 1904. — Triglochin maritimum. Flowering plant 

 growing in a salt marsh. 



which is stouter and larger and is found in salt marshes. Scheuchzeria 

 palustris, a small marsh plant, has been recorded in Britain but is common 

 in the colder parts of Europe. 



Alismaceae 



The members of this family are mostly water or marsh plants, with 

 perennating rhizomes, which are distributed mainly in tropical and tem- 

 perate regions of the northern hemisphere. The family is of particular 



