i8o6 



A TEXTBOOK OF THEORETICAL BOTANY 



rheumatism. The roots contain saponin and those of certain species are 

 crushed and used in washing woollen goods. The family includes two 

 genera, Aescuhis with twenty-five species and Billia with two. The family 

 is essentially American in distribution. Floristically it may be separated 

 from the Aceraceae by the irregular, obliquely zygomorphic flowers and the 

 tricarpellary gynoecium. For the pollination, see Fig. 1700. 



Fig. 1700. — Aescuhis hippocastanum. Pollination. A, Flower in early 

 stage with stamens elongating. B, Later stage with anthers withered 

 and style elongating from among them. 



Turning to those families which comprise the Celastrales we may 

 consider first the Celastraceae. Although this family contains thirty- 

 eight genera and 480 species, few 

 are well known or of economic 

 importance, and we shall confine 

 our remarks to the genus Euony- 

 mus of which there are 100 species 

 distributed in the north temperate 

 region and south-eastern Asia. 



One species, E. europaeus (Fig. 

 1 701), occurs in Britain where 

 it is known as Spindle Tree. 

 Several species produce curious 

 corky outgrowths on the stem. 

 The flowers are bisexual or may 

 become unisexual by abortion of 

 the parts. The perianth is often 

 small and inconspicuous, consist- 

 ing of four sepals and petals en- 

 closing four stamens. The fruit 

 is a five-parted loculicidal capsule 

 which splits to expose red seeds 

 with orange-coloured arils, which 

 ensure dispersal by birds. The 



1 701. — Eiionymus europaeus. Spindle , . 1 ■ ^1 c 4. 



Tree. Flowering shoot. wood IS used m the manufacture 



Fig. 



