1758 A TEXTBOOK OF THEORETICAL BOTANY 



epicarp. The embryo is surrounded by endosperm containing oil and 

 protein. 



The plants are all either trees or shrubs and are characterized by the 

 alternate, simple leaves, which are often strongly aromatic. M. gale is used 

 in medicine. M. cerifera, which grows in North America and is known there 

 as Bay-berry or Wax-myrtle, is a source of wax which is obtained by 

 boiling the fruits. 



FAGALES 



The Fagales are Archichlamydeae in which the flowers are dioecious 

 and form catkins which may be either erect or pendulous. The calyx is 

 much reduced or may be entirely absent. In the female flower there may be 

 an involucre of bracts. The stamens vary from two to many and the ovary 

 possesses from two to six loculi. There are one or two pendulous ovules in 

 each loculus. The seed is non-endospermic. 



This order includes several families among which we shall first refer 

 briefly to the Fagaceae and then consider the Betulaceae in detail. Hutchin- 

 son splits up the Betulaceae into two families by separating out a number of 

 genera into a new family, the Corylaceae. 



The members of the Fagaceae are trees with alternate leaves. They 

 may be either evergreen or deciduous. They are distinguished by the 

 contracted dichasia of 3, 2 or i female flowers which are surrounded by a 

 cupule with numerous imbricated scales or spines. 



The family includes five genera, of which Querciis (Oak), Castanea 

 (Sweet Chestnut), Fagus (Beech) and Nothofagiis are the most important. 

 The genus Pasania is widespread in Malaya and Polynesia. 



In Britain two species of Quercus are considered indigenous, O. robur, 

 the Common Oak, and O. petraea, the Sessile Oak (Fig. 1639), but several 

 other species have been planted. Among commonly cultivated Oaks we 

 may mention O. ilex, the Holm or Holly Oak, which is evergreen. It is used 

 as a timber tree and its bark is employed in tanning. O. cerris (Turkey Oak) 

 and p. alba (Quebec Oak) are both valuable for their timber. The bark of 

 p. suber is used for making bottle cork. It occurs spontaneously in the 

 Mediterranean regions and is cultivated in Portugal and Algeria. The bark 

 of Q. tinctoria forms a yellow dye while O. aegilops is important because 

 the young acorns are employed in tanning. The genus includes some 300 

 species which are distributed through the north temperate regions, Indo- 

 Malaya and around the Pacific. 



The male catkins (Fig. 1640) are borne in the lower foliage or scale-leaf 

 axils of the shoots of the current year, while the female flowers occur in the 

 leaf axils of older shoots. The male flowers are single in the axils of the 

 bracts and have no bracteoles. There are from four to seven perianth seg- 

 ments which are united at the base. The stamens are produced opposite 

 them and are either equal to or more numerous than the perianth segments. 

 The female flowers are solitary and each is surrounded by a cupule bearing 

 numerous scales possibly formed by the union of bracteoles, but the 



