TREES AND SHRUBS. 



409 



leafy shoots, but in April, before the leaves appear, clusters 

 of flowers grow out from the side buds. 



The inflorescence shows the same branching as in Lilac ; 

 the main axis gives off branches which branch again, and the 

 last branches end in flowers. The flowers may be either male, 

 female, or perfect ; the three kinds may be present on the 

 same tree or on separate trees, being grouped in various 

 ways. There are always two 

 stamens in a male or perfect 

 flower (filaments joined below 

 in male flower), while the pistil 

 is bottle- shaped and consists 

 of a two-chambered ovary, 

 tapering style, and two stig- 

 mas. The flowers are mostly 

 wind-pollinated, though ap- 

 parently sometimes visited by 

 insects. 



The fruits are winged akenes 

 (samaras) ; the long and often 

 twisted wing is formed from 

 the top of the ovary and 

 shows at first the remains of 



style and stigmas on its tip. Note the thickened basal 

 part of the key, forming a cavity which contains the single 

 long flat seed. When the seed germinates, the whole key is 

 carried up ; the cotyledons remain inside it at first to absorb 

 the food stored in the endosperm, then come out and form 

 oval green leaves. The first foliage-leaves are three-lobed. 



[397. In the Manna Ash (Fraxinus ornus) of South Europe the 

 flowers have sepals and petals, so that the Common Ash has evidently 

 lost these parts through becoming wind-pollinated. The Ash belongs 

 to the same family (Oleaceae) as Lilac, Jasmine, Forsythia commonly 

 cultivated shrubs Privet (in Britain), and the Olive.] 



Fig. 174. The Ash, with Cluster 

 of Fruits. 



QUESTIONS ON CHAPTER XV. 



1. Name three English trees with which you are thoroughly familiar. 

 Describe the habit, branching, buds, bark, leaves, flowers, and fruit of 

 each. In what sort of situation would you expect to find each grow- 

 ing ? Make your descriptions so clear that the trees could be easily 

 distinguished and identified. 



