CALYCIFLOR.E 239 



or adaptations to cross-pollination make it also one 

 of the most interesting types. It is found in Australia. 

 The only other British species is the Hyssop-leaved 

 Loosestrife, which has flowers as inconspicuous as 

 those of the Water Purslane, which is the third 

 British type of the order Lythraceae. 



The order consists of about three hundred and sixty 

 species and twenty-one genera, which are found in all 

 parts of the world except the coldest regions, but 

 the exotic ones are mainly tropical. 



Trees, shrubs, and herbaceous plants are repre- 

 sented in this order. 



The branches are usually square in section. The 

 leaves are opposite or in whorls, entire, simple, with- 

 out stipules ; or, if present, they are very small. 



The flowers are regular, or zygomorphic, or irre- 

 gular, in racemes, cymes, or panicles. The parts of 

 the flower are in fours, fives, or sixes. The calyx is 

 gamosepalous, inferior, ribbed, with eight to twelve 

 lobes, alternate, with as many teeth (the epicalyx), 

 and tubular or bell-shaped. The calyx-tube is hollow, 

 and persistent. The sepals are valvate, and there 

 may also be an epicalyx made up of combined stipules 

 (as above). 



The corolla is polypetalous, with three to six petals, 

 crumpled in bud, or absent in Water Purslane. The 

 petals are inserted on the calyx-tube. The stamens 

 are perigynous, inserted low down on the axis or 

 calyx-tube, twice as many as the sepals as a rule, six 

 or twelve, or less, or indefinite, and are equal or 



