THE DICOTYLEDONES 



1767 



bracteoles. The female flowers (Fig. 1653) are produced in dense spherical 

 heads and each flower is borne in the axil of a bract. It has no perianth but 

 has two bracteoles and is made up of two carpels, only the anterior one of 



Fic. 1652. — Casua}i?ia sp. Spikes 

 of male flowers. 



Fig. 1653. — Casiiarina equisetifoUa. 

 Short spikes of female flowers ; 

 bracteoles separating to release 

 the winged akenes. 



which is fertile and contains two or more ovules. The flowers are anemo- 

 philous and after fertilization the bracteoles become woody and enclose 

 the winged akenes. The wood is remarkably hard and is known in 

 Australia as She-oak or Beef wood. The young twigs are used to feed cattle. 



MYRTIFLORAE 



The Myrtiflorae are Archichlamydeae with regular flowers, which are 

 often monoecious. The corolla is polypetalous and pentamerous except in 

 the Lythraceae where the flowers have six petals. The stamens may vary 

 considerably in number, being very numerous in the Myrtaceae. The 

 ovary may be unilocular or multilocular, with a single style, except in the 

 Haloragidaceae. There are usually numerous anatropous ovules with axile 

 placentation. The seed is usually non-endospermic. The plants may be 

 trees, shrubs or herbs. 



It will be seen from the above diagnosis that the limits of the order are 

 very wide and it is not surprising therefore to find that some twenty-two 

 families have been included in it. Several of these are of minor importance 

 and we may leave them out of our consideration. According to Engler the 



