120 WONDERS OF PLANT LIFE 



to the student the leaf ancestry of the sepals and 

 petals. 



A singular example of a plant belonging to 

 an advanced family which has not found it neces- 

 sary to produce any coloured sepals or petals 

 for its flowers at all is to be seen in the Green 

 Rose (Rosa viridis). As the name of the plant 

 suggests, it is entirely without any tinted blooms, 

 all parts of the flower being in the form of small 

 green processes. If examined closely the organs 

 are seen to be nothing more than diminutive 

 leaves, and these even go so far as to retain the 

 toothed edges which are such familiar features of 

 rose foliage. 



The change of the leaf into a tinted sepal or 

 petal is not, after all, such a very remarkable 

 happening, for coloured leaf-like organs, which 

 exhibit their character in all respects save that 

 they are not green, are not uncommon. One of 

 the most striking plants exhibiting this change of 

 colour in the leaf is the Bougainvillea glabra, 

 examples of which are to be seen fairly often in 

 greenhouses. The real bloom of the Bougain- 

 villea is insignificant, nothing like so striking in 

 appearance as our Cowslip. They are developed 

 in clusters of three, and, being of a pale yellow, 

 would scarcely be noticed amongst the foliage 



