€98 ZONES OF ALPINE VEGETATION. 



and Ribes, form the upper limit of shrubs, at 11,500 feet; on the 

 north, Genista versicolor ascends to 17,000 feet. 



The following have been given by some authors as the zones of 

 Alpine vegetation : — 



1. Region of Lowland cultivation. Its extent of elevation is at the spot where 



the prevailing cultivated plants of the latitude cease to he productive. In 

 mount .ffitna, it rises to 3300 feet ; on Teneriife to nearly 3000 (zone of 

 vines). It embraces two zones of the Cactus and Euphorbia in the Canaries. 

 In Madeira it embraces two regions of Spix and Martins ; the region of tro- 

 pical plants reaching to 700 feet, and the region of the vine, fruit, and com, 

 to 2300. In Norway, Sweden, and Pinmark, it is narrow. In the Carpa- 

 thians it rises to 1500 feet. Within the tropics it is a broad and import- 

 ant region. On the Andes, at Quito, it only ceases at 6000 or 6000 feet. 



2. Region of Woods. A magnificent region in all Alpine districts, and well charac- 



terised on the Andes and Himalaya. In the Andes it reaches to 10, 800 feet, 

 and is characterised by Escallouia myrtilloides, AraUa avicennif olia, and Dry- 

 mis Winteri ; on the mountains of Mexico to 12,000 feet, and is marked hy 

 Finns Montezumse. Humboldt notices this region in Teneriffe. In JEtna it 

 extends to 6200 feet ; in the Canaries to 4080 ; in Madeira (region of 

 chestnut) to 2950. In Lapland it extends to 800 feet ; in Pinmark 70° 

 north latitude to 730. 

 5. Region of Shrubs. Region of Retama (Spartium nubigenum) in Teneriffe. On 

 the Pyrenees and Mont Blanc, it is extensively covered, to about 8500 feet, 

 with Rhododendrons. In the Andes, about Quito, it reaches 13,000, and is 

 conspicuous for its Bej arias and shrubby Compositse. In Madeira it embraces 

 Kuhl's regions of Spartium and Heath. On the Mountains of Lapland it 

 attains from 2000 to 3000 feet, and is characterised by Betula nana, Vaccin- 

 nium, and Salix. In Pinmark its limits are 1100. As Rhododendron hirsutum 

 and ferrugineum succeed the arborescent region of the Swiss Alps, and R. 

 ferrugineum that of the Pyrenees, so does R. Lapponum succeed the Conifers 

 in Lapland, and R. caucasicum on the Caucasus. 



4. Region of Grasses. These predominate in certain Alpine situations, and in cer- 



tain parallels of latitude. In South Shetland, none of the islands exhibit 

 any Phanerogamous vegetation, with the exception of straggling grass. In 

 Melville Island, 75° north latitude, the proportion of grasses to Phanerogamous 

 plants is 1 to 5 ; in Great Britain, 1 to 12^. In the Andes the region is 

 traced to Paramos, and occupies a space of 13,000 to 14,500 feet ; here are 

 large cattle farms. In the^Himalaya a fine greensward is often seen at 14,600 

 feet. In Tenerifl^e, it is distinguished by Humboldt. On the Swiss Alps, 

 Poa annua exists at an elevation of 7400 feet. 



5. Region of Cryptogamous plants. This is well marked in many places. Colonel 



Hall, on Chimbora90, imder the Equator, at nearly 16,000 feet, found Draba 

 aretoides, and Culcitium rufescens ; still higher, a moss, whioh| may be con- 

 sidered as having attained the highest limit on the globe at which vegetable life 

 exists. Lichens are the latest plants met vrith in ascending Teneriffe, the 

 Himalaya mountains, and the .Alps. 



In the mountains of the torrid zone, the following regions are 

 described by Meyen, corresponding to the zones given in his latitudinal 

 range of vegetation (page 692) : — 



1. The region of Palms and Bananas, extending from the level of the sea to 1900 



feet of altitude It corresponds to the Equatorial zone. 



2. Region of Tree Ferns, and species of Ficus, extending from 1900 feet to 3800. 



(Tropical zone. ) 



