ASIATIC CONIFEES. 183 



for the most part among conifers. If cold latitudes produce broad-leaved evergreens, 

 they are for the most part decumbent shrubs, which grew in forests under the shelter 

 of other trees. Glancing at the opposite latitudes — the tropics — we may at first sup- 

 pose the case is different, as in the hotter parts of South America, East and West 

 Indies, the trees have broad, expansive foliage. But here it should be borne in mind 

 that the atmosphere is extremely humid, which counteracts the effects of intense heat 

 upon the foliage. Recent explorations in Australia tell us that the heat of that coun- 

 try is much greater than those I have been describing; indeed, among the hottest in 

 the world ! This intense heat is extremely arid, and must as a consequence be very 

 trying to vegetation ; but nature ever correct has given a twist to the petiole or stalk 

 of the leaf, which makes that stand on edge, with both sides equally exposed to tlie 

 air and light, and both sides of the leaf are much alike. This is more generally true 

 of the trees of Australia, but not of the shrubs. Now for what purpose has nature 

 done this, if not to turn off the intense arid rays of a burning sun, which would 

 under ordinary circumstances destroy the foliage ? From this I think we may argue 

 that small-leaved trees, such as conifers, will also stand more heat and sun than broad- 

 leaved trees of these regions; and this class of trees we may expect more adapted to 

 our climate, which proves to be the case. 



The native evergreens of this country, as the American arbor vitse, American yew, 

 white pine, and even the most beautiful of our evergreens the hemlock spruce, have a 

 pale rusty brown appearance during the winter. Many will perhaps think I am not 

 doing the hemlock justice in writing thus much ; but had they seen it grouped side 

 by side with the dark, rich, grassy green foliage of the Californian pines, such as 

 Pinus insignis, or many of the eastern conifers, they would see more plainly the force 

 of my remarks. It is not my wish to depreciate the beauty of this tree, if I could do 

 so ; beautiful it truly is, yet justice compels me to say, in point of coloring it must 

 give place to the conifers of other regions. What are the causes which produce this 

 rusty appearance I have been describing ? I have no hesitation in ascribing it to the 

 cold of winter. The Cryptomeria Jajponica is a good illustration of this. Grown in 

 the open air in this country or Britain, it assumes that disagreeable rusty appearance 

 through winter ; in a green-house it retains its green color through winter, also in 

 some of the milder parts of Britain. I have seen plants in the open air in that coun- 

 try as rich a green in the month of March as they had been in the early fall previous. 

 This I have observed upon the same grounds, — where the plants were sheltered, they 

 retained their green appearance ; where more exposed, they became rusty. California 

 having a nvild climate, its native trees retain through winter their rich green appear- 

 ance. This the conifers from the Mexican mountains also do, as well as most of the 

 conifers and other shrubs of Europe. The Himalayan conifers retain as well through 

 winter their beautiful green. Not so with the conifers from China; most assume in 

 winter and early spring that disagreeable appearance I have been describing. What 

 cultivator has not observed this with the Chinese arbor vita) {Biota oricnialis)'i In 

 early spring, after passing through a severe winter, this appearance is common to it, 

 though in the previous fall it had a beautiful green appearance. The case of the 



