B. P. I.— 802. 



THE CHINESE WOOD-OIL TREE. 



INTRODUCTION. 



The Chinese wood-oil or tung-oil tree (Aleurites fordii) is grown on 

 the heavy-clay hillsides and waste places along the Yangtze River 

 above Hankow, where the rainfall is heavy and the climate is similar 

 to that of some of our Southern States, although the temperature 

 does not go so low in winter. The tree is probably not very long- 

 lived and would be comparable in this respect to the silver maple. It 

 drops its leaves in winter and does not wake up early in the spring, 

 like many trees, and therefore is not likely to be severely injured by 

 late frosts. 



The flowers come out before the leaves. They are fully as large as 

 catalpa flowers, and the tree in bloom is a very pretty sight. As an 

 ornamental the wood-oil tree (Pis. I and II) is likely to prove about 

 as desirable as the catalpa, but the soft wood is of little value and, 

 like many other soft-wooded trees, the branches break off easily in 

 heavy winds. 



The Chinese wood-oil tree commences to bear fruit when 4 or 5 

 years old. The fruits are the size of small apples — from 2 to 3 inches in 

 diameter. (PI. III.) They contain from two to eight (most commonly 

 five) large, oily seeds, that are reported to be poisonous and should 

 not be eaten. They at least have a purgative effect, similar to that 

 of the castor bean, to which the wood-oil tree is botanically distantly 

 related. The yield of these nuts in China is reported to be from 30 

 to 75 pounds per tree. 



ECONOMIC VALUE OF WOOD OR TUNG OIL. 



The value of this Chinese tree lies in the fact that the nuts contain 

 one of the best drying oils known, called wood or tung oil. In recent 

 years this oil has produced, it is reported, a revolutionary effect on 

 the varnish industry of the United States. It has largely taken the 

 place of kauri gum and has made possible the manufacture of a 

 quicker drying varnish, which is less liable to crack than that made 

 from kauri gum, and has been found of special value in waterproof 

 priming for cement. 



72160°— Cir. 108—13 3 



