THE DICOTYLEDONES 



1809 



The Empetraceae are an even smaller family with three genera, 

 Corema, Efnpetrum and Ceratiola. Ceratiola is monotypic, while Empe- 

 trum and Corema have two species each. Empetriim nigrum occurs in Britain 

 and is called the Crow-berry. It is a typical component of peaty moorland 

 vegetation. The flowers are produced on spur shoots and are trimerous. 

 The leaves show xerophytic modifications, with a well-developed cuticle 

 and stomata sunk in deep grooves, lined with hairs, formed by the down- 

 wardly rolled leaf margins. 



We may also refer here to the Buxaceae, a small family whose systematic 

 position is very doubtful. Placed in the Sapindales by Engler, it was 

 included in the Euphorbiales by Rendle and in the Hamamelidales by 

 Hutchinson. It is a family of evergreen shrubs with leathery leaves and no 

 latex. There are six genera and about thirty species widely distributed in 

 the temperate and tropical parts of the world. 



The genus Biixus includes B. semperzirens (P^ig. 1705), Box, w^hich occurs 

 w^ild in certain southern countries and is often cultivated. It grows very 

 slowly and the box hedges which are found in the gardens of old mansions 



Fig. 1705. — Buxiis semperzirens. Box. Left, a flowering shoot. Right, a shoot with 



ripe capsules. 



may have been planted for several hundred years. The wood is very firm 

 and close grained and is largely used in turning and for wood-block 

 engraving. The common name is a corruption of the German " Buchs " 

 (Books), from the last-named use. 



Somew'hat closely allied to the Sapindales, though occupying a doubtful 

 position, are the Santalales. The members of this order may be trees, 



