516 AMERICAN JOURNAL OF BOTANY [Vol. io. 
As might be expected from its great isolation, New Zealand, like Aus¬ 
tralia, has a very high percentage of endemic species. According to Cock¬ 
ayne, 1 of the vascular plants 74 percent are endemic, and, if only seed-plants 
are considered, 79 percent. Of the dicotyledons, no less than 85 percent 
are peculiar. 
The mean annual temperature of Auckland, in the North Island, is 
59.2 0 F. (February, 67.i°-July, 51 °); Invercargill, in the extreme south 
of the South Island, io° farther south, has a mean temperature of 50° 
(February, 56.6°-July, 41.2°). 
The rainfall is largely controlled by the position of the mountain ranges. 
The prevailing winds are westerly, and the west coasts receive a maximum 
rainfall; but in the South Island, especially, the extensive lofty range of the 
Southern Alps, parallel to the West Coast, intercepts a large amount of the 
moisture, so that, while stations to the west may have 200 inches of rain 
annually, eastern stations like Christchurch may show only 25 inches, or 
even less. The average throughout New Zealand is 40-50 inches, with a 
pretty even distribution through the year, although the autumn and winter 
are somewhat wetter, and the summer is the dryest season. 
The main range of mountains in the North Island extends from the 
extreme south to about the middle, following the east coast, but much lower 
than the Southern Alps, the highest peaks being under 1800 meters. 2 The 
loftiest mountains of the North Island are volcanoes arising from a plateau 
in the center of the island—the Rotorua district celebrated for its volcanoes, 
geysers, and hot springs—a region familiar to tourists visiting New Zealand. 
Ruapehu, 2803 meters elevation, is the highest mountain of the North 
Island, and its summit is permanently snowclad. Some small glaciers also 
occur. Mt. Egmont, on the west coast, is a fine volcanic cone 2514 meters 
in height, and also crowned with perpetual snow. In general, the surface 
of the North Island is very rugged, with relatively little level country. The 
most extensive level region is the Wanganui Plain, sloping gradually from 
the western coast to Mt. Ruapehu. Streams are abundant, but none of the 
rivers are of great length, owing to the limited size of the island. Lakes 
are not infrequent, the largest being Lake Taupo, on the volcanic plateau. 
The South Island is not only larger than the North Island, but the 
mountains are much higher. The Southern Alps extend for nearly the 
whole length of the island parallel with the west coast, and culminate in Mt. 
Cook, 3766 meters. Both because of the greater elevation and of the 
higher latitude, these mountains are permanently snow-clad, and from them, 
in the southern portion, descend great glaciers reaching almost to sea level. 
The Franz Josef glacier terminates at 218 meters above the sea. To the 
east of the Alps are extensive plains, the most important being the Canter¬ 
bury Plain, 48 kilometers across in its widest part. To the west of the moun- 
1 Cockayne, L. Vegetation of New Zealand. Die Vegetation der Erde 14: 311: 1921. 
2 Cockayne, loc. cit., p. 23. 
