GEOGRAPHICAL SITUATION OF PLANTS. 
213 
ture, some will grow only in mild and temperate climates, and oth- 
ers only in the midst of frost and snows. 
Thus every country where man is to be found, has its vegetation. 
Some species, with respect to localities, are confined to narrow limits. 
A species of Origanum (the Tournefortii) was discovered by Tour- 
nefort, in 1700, upon one single rock in the little island of Amorgos, 
in the Greek Archipelago ; eighty years afterward, the plant was 
found in the same island, and upon the same rock, and has never 
been discovered in any other situation. Some plants confine them- 
selves within certain longitudes, scarcely varying to the right or 
left. The Menziesia j9a//?/o/?'a, a species of heath, confined between 
ten and fifteen degrees of west longitude, is found in Portugal, Spain, 
and Ireland. Latitude and elevation, by reason of mountains and 
table lands, produce a greater variety in the appearance of vegeta- 
tion than almost any other causes. 
Few plants are found to endure extreme cold. Botanists former- 
ly estimated, that at Spitsbergen, in north latitude about 80°, there 
were but about 30 species of plants,* in Lapland, in 70°, 539 species ; 
at Madagascar, at the tropic of Capricorn, 5000 ; and at the equator 
a much greater number. These estimates fall very far short of the 
number of species now known, but they may give some idea of the 
difference in the vegetation of cold and warm climates. 
Geographical situation of Plants. 
^.Every country exhibits a botanical character peculiar to itself. 
Linnaeus, in his bold and graphic language, said,t " A practical bo- 
tanist can usually at the first glance distinguish the plants of Africa, 
Asia, America, and the Alps ; but It Is not easy to tell how he is able 
to do this. There is a certain character of snllenness, gloom, and ob- 
scurity in the plants of Africa ; something lofty and elevated in those 
of Asia, sweet and smiling in those of America; while those of the 
Alps seem rigid and stinted." 
In investigating the geographical situation of the vegetable king- 
dom, we see the powerful effects of light and heat. Feeble in the po- 
lar regions, vegetation acquires strength as we approach towards 
the equator, where the Ught of the sun is vivid, and its heat perma- 
nent and intense. 
The centre of the frigid zone is entirely destitute of vegetation. 
After passing the arctic circle, we find on the borders of the temper- 
ate zone a few species of plants, chiefly lichens, mosses, and ferns, 
also a few shrubs and berries. In the heat of a polar summer, the 
growth of plants is rapid ; Lapland is the only country within this 
zone where any kind of grain can be raised. 
The productions of the temperate zone gradually alter in character 
as we approach the tropics. Humboldt has divided the temperate 
zone, with respect to productions, into three regions ; the cold, the 
temperate, and warm regions. In the cold region, grain may be 
raised to advantage, and berries grow in abundance. In the tem- 
perate region, the wine, grape, grain, and fruits of many kinds, are 
cultivated in their greatest perfection. The warm region produces 
olives, Jigs, oranges, and lemons. 
* That is, exclusive of the Cryptogamous plants. 
t " Primo intuitu distinguit ssepius exercitatus botanicus plantas Africae, Asiae, Amer 
ica, Alpiuinque, sed non facile dicerit ipse ex qua nota. Nescis quae facies torva, sic 
ca, obscuris Afris ; quae superba, exaltata Asiaticis ; quae laeta, glabra Americanis ; 
quae coarctata, indura Alpinis." 
Some plants have a confined locahty— Few endure extreme cold— Every country 
has its oyvn botanical character— Plants of the frigid zone— Temperate zone. 
