18 



to be 50 feet (15 meters) in height, with trunks t3 inches to 1 foot (15 

 to 30 cm.) in diameter. The wood is very durable and is on that 

 account prized for fence posts and railway ties, for foundation walls, 

 and for making shingles. The wood itself is rather coarse, yellow 

 brown, and is free from resin ducts. The trees are grown as orna- 

 mental trees, particularly in the form of hedges. 



WHITE PIXE. 



The White Pine, Pirrns strobus L.. once so large a factor in the lum- 

 ber industry of the New England States, is now comparatively rare as 

 mature timber. It is subject to a number of diseases which will be 

 treated of in a special paper. It is left out of consideration on that 

 account in the present report. 



TA3IAIIACE:. 



The Larch, or Tamarack. Larix laricina (Du Roi) Koch (Z. ameri- 

 cana Michaux),^ is a tall, stately forest tree which is found grooving 

 with the White Pine and Spruce and in some sections forms extensive 

 forests, especially in low swampy lands. It grows throughout the 

 Northern States, ranging from Maine westward to the western slopes of 

 the Rocky Mountains, and southward to northern Pennsylvania, Indi- 

 ana, and Illinois, and to central Minnesota. As an ornamental tree it 

 is highly prized because of its graceful habit and thrifty growth. The 

 wood of the Tamarack is extensively used in shipbuilding, for railway 

 ties, and telegraph poles. It is very durable and hard. Compared with 

 the White Oak, it has a crushing strength of 1.38. Dudley^ says of it: 



The quality of the wood of this tree is such that it deserves to be widely known 

 and more extensively used for ties than it has been. * * * The wood is easily 

 treated with antiseptics to prevent decay, especially with sulphate or acetate of iron, 

 and ties so treated have lasted over thirty years under heavy traffic. 



POLYPORUS SCHWEINITZII Fr. 



Polyporus schweinitzUFT., Sjst. 1:351. 

 Polyporus schweinifzii Fr. , Epic. 433. 

 Boletus sistotremoides Alb. and Schw. , 243. 



[Figured in Fries' s Icon. Hym. No. 179.] 

 OCCURRENCE. 



This fungus is one which is very common throughout the Northern 

 forests on the Spruce and Fir, and, as Dr. Farlow remarks.^ appears 

 to be very much more prevalent in this country than in Europe.* It 

 certainly stands near the top of the list in point of destructiveness. 



1 Sargent, C. S. Silva of North America. 12:7. 1898. 



2 Dudley, P. H. Bui. No. 1, Division of Forestry. Appendix I. ol. 

 ^Sargent, C. S. Silva of North America. 11 :li. 1897. 



*Hartig (Lehrbuch der Pflanzenkrankheiten. 177. 1900) says it occurs only on 

 Pines. 



