CENTRAL AMERICA 127 



and tobacco, papaw, mango, &c. : rice is, on the whole, 

 seldom grown. This kind of vegetation may be carried 

 to elevations of 2,500 to 3,000 feet. 



The slope of the hills, especially where the gradient is 

 very steep, is covered with sparse forests of evergreen 

 oak and strawberry-tree (arbutus), or other short, stout 

 trees, resembling in many ways the Mediterranean oak 

 woods. Farther up, the tropical pines make their 

 appearance, and constitute a zone of tall, gloomy forests 

 with little undergrowth. At about 3,000 feet the rain- 

 forest changes its character, and tree ferns, small 

 palms, and bambus become conspicuous in the under- 

 wood, whereas epiphytes, lianas and climbers decrease 

 in size, if not in diversity and number. Higher again 

 this warm rain-forest gives way to another less profuse 

 and lower variety, in which the number of leaf -shedding 

 trees increases until they are in turn replaced by pine 

 forests on the drier ridges. 



The high wind-swept plateaus are either lightly 

 covered with thin and stunted pine woods, as in the 

 north of this region, or, at greater elevations, merely 

 clad with a heath-brush, suggesting a bilberry heath. 

 The sierras which rise above the timber line are capped 

 by an alpine zone. Of the Colombian paramos, the 

 lowest may present the appearance of an open bush- 

 prairie, while the highest display a truly alpine carpet 

 of stunted heath, wool-clad plants, low tussocks of stiff 

 grass, or cushion plants scattered over the bare floor. 

 Among these, in groups or solitary, stand the curious 

 ■ frailezones ', with stout, shaggy bodies, and woolly 

 heads. 



In all this region, the inland valleys are, as a rule, 

 much drier than the Atlantic slopes, except where they 

 are open to the north and north-east winds. The 



