i888 A TEXTBOOK OF THEORETICAL BOTANY 



and Jasininum a berry; in Olea a drupe; in Fraxinus a samara. The berry 

 in Jasminum is vertically constricted giving the appearance of a double 

 structure. 



The seeds are endospermic, the reserve material being oil, except in 

 Jasmimim, and the embryo is small and straight. 



The family contains about 400 species distributed among twenty-one 

 genera. They are found in temperate and tropical regions but the main 

 centres of distribution are Indo-Malaya and the Sino-Japanese region. 

 Economically the most important genus is Olea, for O. eiiropaea is the Olive 

 of commerce. It is a tree which may reach a very great age. It is probably 

 a native of Abyssinia whence it was introduced into the Mediterranean 

 regions of Europe during the first century before Christ. The olive oil 

 is obtained by pressing the fleshy fruits. There are actually two forms which 

 may be distinct species. The wild form has thorny twigs and small fruits, 

 while the cultivated form is smooth and has large fruits. O. laurifolia 

 yields good timber known as Black Ironwood. The presence of peltate 

 hairs is an anatomical feature common to all members of the family, while 

 the absence of bicollateral bundles distinguishes this family from the 

 Gentianaceae, Loganiaceae, Apocynaceae and Asclepiadaceae, and the 

 absence of laticiferous tissue separates it from the Styracaceae and 

 Ebenaceae. Sclerenchymatous fibres often occur in the leaf mesophyll. 



The family is classified as follows, mainly on the nature of the fruit 

 and on the position of the seed. 



I. Oleoideae 



Seeds pendulous. Fruits not vertically constricted. 



1. Fraxineae. Fruit a samara. Only genus Fraxinus. 



2. Syringeae. The fruit is a loculicidal capsule. Syringa and Forsythia. 



3. Oleeae. The fruit is succulent, either a berry or a drupe. Olea 



and Ligustriim. 



Fig. 1 801. — Jasminum officinale. Flowering shoot. 



