BOTANICAL SYNOPSIS 161 



NATJJRAL OSDEK, ULMAGB^ (ELM FAMIL7). 



Ulmua Burculosa Stokes.— Common Elm. Bark furrowed. 

 Suckers. Branches often long and horizontal. Leaves 

 alternate, oblique, irregularly serrate, acute, variable in size. 

 Flov^ers preceding the leaves, vinous red. Fruit a samara, 

 winged all round, obovate, with the seed above its centre. 

 March, April. Middle and Southern Europe, Siberia, and 

 North Africa. — Vol. I., j). 41. 



U. montana Stokes. — Wych Elm. Bark furrowed. No 

 suckers. Branches ascending and pendulous. Leaves and 

 flowers much as in the above. Samara sub-orbicular, with 

 the seed below its centre, more often ripening. March, 

 April. Europe and Siberia.— Vol. III., p. 81. 



NATURAL ORDER, BETULACE^ (BIRCH 

 FAMILY). 



Betula alba L. — Birch. Bark smooth, silvery-white, 

 scaling off in transverse strips. Branches copper-brown, 

 often weeping. Leaves alternate, deltoid or rhomboid, irregu- 

 larly serrate, on long stalks. Flowers monoecious. Male 

 catkins one to two inches long, pendulous. Female catkins, 

 sub-erect at first, their scales deciduous. Fruit minute, 

 winged. April to May. Europe and North Asia. — Vol. III., 

 p.\. 



Sub-species B. verrucosa Ehrh. — White Birch. Leaves 

 truncate at the base, acuminate, with raised veins. — Vol. III., 

 p. 4. 



Sub-species B. glutinosa Fries. — Leaves cordate-acute, 

 with veins on the under surface. — Vol. Ill, p. 1. 



Alnus glutinosa Gaertn. — Alder. Bark black, with clefts. 

 Branches triangular when young. Leaves alternate, obovate, 

 blunt, wavy, serrate, glutinous when young, dark. Flowers 

 in monoecious catkins. Female catkins not an inch long,, 

 their scales woody and persistent. Fruit hardly winged. 

 March, April. Europe, Asia, and North Africa. — Vol. III., 

 p. 97. 



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