PERIODICAL LITERATURE 1041 



B. Young twigs slight!}' tomentose, or hirsute. 



a. Leaves blue-green,^ young twigs reddisli 



brown. 



1. Leaves about 2 to 3.5 cm. long.. .L. leptolepxs (6) 



2. Leaves about 2 cm. long L. kiirilensis (15) 



b. Leaves green. 



1. Ends of branchlets pendulous, 



when young reddish brown, 

 slightly hirsute, leaves up to 4 

 cm. long L. griffithii (4) 



2. Branchlets not pendulous, rigid, 



when young yellowish brown, 

 pubescent, leaves up to 3 cm. 



long L. occidentalis (i) 



IL Young twigs glabrous. 



A. Leaves relatively long, 3 to 5 cm. Dry twigs 



have strong odor of jasmine L. sibirica (10) 



B. Leaves of medium length, 2.8 to 3.5 cm. Fresh 



twigs have slight odor of balsam L. dahurica (12) 



C. Leaves relatively short, seldom over 3 cm. 



a. Young twigs grayish yellow. Dry twigs 



often with slight jasmine odor L. europece (7) 



b. Young twigs reddish brown (small 



cones) L. americana (18) 



In considering the availability of the various larches in forest man- 

 agement in Sweden, Schotte reaches the following conclusions : 



Larix europece is cultivated in nearly all parts of Sweden, as far 

 north as Pitea, and even to a limited extent in Haparanda. In the more 

 remote portions of Norrland it is seldom found. Planting was begun 

 in 1750, though the first forest plantations were not established until 

 1780. Most of the seed for this early planting was obtained from 

 Scotland. The resulting stands are especially noted for their tall, 

 straight boles and thin crowns. These characteristics are so pronounced 

 that Schotte asserts that a special Scotch variety of Larix europece must 

 be recognized. 



Since the middle of the nineteenth century a large proportion of the 

 larch seed used in Sweden has been obtained from Tyrol. The result- 

 ing larch stands contain a high percentage of crooked and illy formed 

 ])oles, while the height growth is inferior and the crowns are bushier. 

 These characteristics make the Tyrolean larch unsuitable for mixed 

 forests and a poor tree from the standpoint of timber production. 



Scotch larch can advantageously be grown on the best forest soils, 

 ^lerchantable logs are quickly produced in about a third less time than 

 is required for Baltic pine. As larch is very subject to a disease known 

 as "larch cancer" (caused by an ascomycete, Dasyscypha zvillkommii 

 Hart), Schotte states that it should be planted in admixture with other 



* The green-leaved forms of these species prove exceptions. 



