50 AFRICAN GAME ANIMALS 



pressure of heavy masses of snow which must be borne for 

 several months. Such a condition never occurs in tropical 

 Africa, where the snow-fields are constant in area and far 

 removed from the forests. Only the herbaceous moorland 

 vegetation reaches the snow-fields, but does not mix with 

 them. 



The moorland which rises above the bamboo zone is a 

 well-marked treeless belt extending from ten thousand 

 feet to the snow at fourteen thousand five hundred feet. 

 It is divisible into two lesser floral zones: a lower tree-heath 

 belt ranging up to twelve thousand feet and a higher zone 

 reaching to snow-line, characterized by the presence of the 

 tree Senecios. The vegetation in the moorland zone is 

 closely allied to that of the alpine regions of Eurasia and 

 North America. Many of the genera and a few of the 

 species which occur are common also to the north temperate 

 zone. The great bulk of such plants belong to the orders 

 Rosacece and EricacecB. The dominant shrub or small tree 

 of the lower zone is Erica arhorea^ a species found also in 

 the alpine regions of southern Europe. Several species of 

 the wide-spread holarctic genus Alchemilla form the carpet 

 of the moorland. A. argyrophylla, a stout, shrubby species, 

 is the chief of these and grows in a dense mat one or two 

 feet in depth over the entire area of the tree-heath zone. 

 Another European genus, Hypericum, commonly known as 

 Saint-John's-wort, occurs abundantly in the form of small 

 trees at the lower or timber-line edge of the heath zone. 

 Hypericum lanceolatum is an abundant tree, and its large 

 golden flowers, which are borne in great profusion, give the 

 lower alpine region a striking appearance. A small gray- 

 leaved tree, allied to our sage-brush, Stobe kilimandcharica. 



