THE DICOTYLEDONES 1799 



We shall not consider any one of the families in detail but shall refer 

 briefly to certain of the more important ones. 



The Anacardiaceae are a family of about sixty genera and 500 species 

 whose distribution is mainly tropical, although a few are found in southern 

 Europe. They are mainly trees or shrubs and are characterized by the resin 

 canals which are present in the wood. The flowers are hermaphrodite 

 though they mav become unisexual by reduction of the parts. There may 

 be from three to seven petals, though the corolla may be absent, and the 

 stamens are often double the number of the petals. The ovary is superior 

 and contains a single, solitary, pendulous ovule. The flowers are sometimes 

 epigynous. The fruit is usually a drupe and the seed has little or no 

 endosperm, while the embryo has fleshy cotyledons. 



Among the numerous plants of interest which belong to this family we 

 may mention first the genus Rhus, of which there are about 130 species 

 wddely distributed in warm temperate and subtropical regions. In this 

 country the best known is R. cotimis (Fig. 1692), the so-called Burning Bush 



'\ 



Fig. 1692. — Rhus cotiuus. Inflorescence. 



or Wig Tree, which forms a large shrub often grown in gardens. The name 

 Wig Tree has been given to the plant because of the way the fruits ripen. 

 The stalk of each drupe remains smooth, but the sterile part of the panicle 

 lengthens and becomes hairy. When ripe the stalks become detached at the 

 joints and the whole inflorescence with the fruits attached falls to the ground 

 and may be blown about. These structures have the semblance of grey 

 wigs. The wood yields the yellow dye known as " Young Fustic". R. 



