THE DICOTYLEDONES 



1879 



absence of internal phloem, and the dimerous androecium, which he 

 considered to be an advanced character. Hence he separated the Oleaceae, 

 with the additional family Salvadoraceae, as the Oleales, while retaining 

 Engler's Contortae for the other four families. This view was followed by 

 Rendle. Hutchinson placed the Oleaceae and Loganiaceae in the Loga- 

 niales and the Apocynaceae and Asclepiadaceae in the Apocynales, while 

 the Gentianaceae he placed in the Gentianales between the Compositae and 

 the Primulaceae. 



In this book we shall consider in detail only the Oleaceae and shall 

 refer briefly to certain features of interest in other families; hence for 

 convenience, though not necessarily on systematic grounds, we shall treat 

 them under the heading of the Oleales. 



The Loganiaceae are a small tropical family with thirty-five genera and 

 about 600 species, which are characterized by having flowers with four or 

 five petals and stamens, a bilocular ovary and ovules indefinite in number. 

 The fruit is a capsule, berry or drupe and the seeds are endospermic. The 

 plants are mostly trees or shrubs, which bear cymose inflorescences. The 

 best-known genus is Buddleia with about 100 species which are generally 

 distributed in the subtropics (Fig. 1788). Several species are commonly 



Fig. 1788. — Distribution of Buddleia. 



cultivated in gardens, the most common being B. variabilis (Fig. 1789), a 

 native of China, which bears long inflorescences of mauve flowers, and 

 B. globosa (Fig. 1790) which comes from Chile and Peru and produces balls 

 of orange-yellow flowers. Several other Chinese Buddleias are in cultiva- 

 tion, but they are delicate and require protection in winter. The flowers are 

 pollinated by butterflies, and in the late summer attract large numbers of 



2D 



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