ILLUSTRATIONS. 9 



calyx and corolla, the former consisting of five green sepals, 

 the latter of five coloured usually purple or white petals, which 

 form an irregular flower, two of the petals being placed to form 

 the upper half, and of the remaining three which form the 

 lower part, the lowest is extended backwards at the base, pro- 

 ducing a kind of spur. The Violet has therefore an irregular 

 polypetalous spurred corolla. There is also a peculiarity in the 

 anthers, which are five in number, and are more or less closely 

 joined in a sort of ring around the ovary, the two lowermost 

 of the five being, like the lower petal, lengthened into a spur. 

 These spurred polypetalous flowers serve to distinguish the 

 Violets from all other British plants except the Balsams, 

 which are known by having only three sepals and three petals, 

 all coloured. 



The Sycamore* illustrates another family of the same 

 group the Polypetalous Exogens, namely, the Aceraceous or 

 Maple family. This is a well-known tree, very extensively 

 planted in this country, seeding readily and springing up from 

 self-sown seeds so freely that it may be regarded as naturalized 

 here, though the mountains of central Europe and western 

 Asia have been its ancient home. This tree, which flowers 

 early in spring, puts forth broad palmately-lobed leaves, and 

 bears rather inconspicuous flowers in pendent clusters, which 

 look not unlike immature bunches of small grapes. The in- 

 dividual flowers consist of five small green sepals, five small 

 green petals, and about eight stamens inserted on a thickened 

 disk around the ovary. The fruit of these plants consists of 

 two carpels, each extended into a wing at top ; they are popu- 

 larly called keys, but in technical language such a fruit is 

 called a samara. 



Along with the Wood Anemone, already adverted to, may 



* Acer Pseudo-platanus Plate 2 B. 



