Responsive type of vegetation. Stems always short. 
Ist. Radiate dwarf cushion type. 
and. Rosette type. 
ard. Succulent type (Saxifrages). 
Ath. Reduced leaf system (Cassiope). 
5th.. Grasses like those of arid region. 
Resistance to cold. 
Plants have specific power to resist cold. 
Flowers. : 
Generally brighter in color than temperate or tropical flow- 
ers. 
Usually larger in proportion to size of stem and leaves. 
Warm oases. 
1. Protected from wind. 
2. Slope toward south. 
3. Ground thawed to greater depth. 
7 4. Encourages a more luxuriant vegetation. 
2) pine Plamt Societies. 
Schimper's divisions of mountains. 
1. Basal region—analogous in climate to lowlands. 
2. Montane region—analogous in climate to high places in 
lowlands. 
3. Alpine region—no analogy in lowlands. 
a. In passing from basal to aipine region note zonal 
arrangement. 
b. General resemblance to arctic vegetation but 
different adaptations. 
Salix polaris and Saxifraga oppositifolia. 
Aerial parts more weakly developed in 
polar lands. 
Alpine character due more to physiological 
causes than to heredity. 
Factors of alpine climate influencing plants. 
Ist. Decrease in precipitation. 
2nd. Decrease in heat. 
3rd. Rarity of atmosphere, favors, (Results in great 
4th. Strong solar radiation, and | 1change tempera« 
sth. Strong radiation from ground. | | ture night andday. 
6th. High winds. 
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