AND U. S. EXPERIMENT STATION. 25 



few years, and is apt to form forked branches; usually one of the 

 branches will take the lead, in which case pruning is unnecessary; but 

 if two branches of equal strength grow up, one should be cut off. The 

 white elm is universally recognized as one of the very best lawn and 

 street trees in America. 



Box ELDER. I have been often asked to recommend a variety that 

 will take the place of box elder. The objections to this species are its 

 small size when mature, low trunk and poor quality of timber. It is 

 harder to prepare for the stove than cotton wood and makes no better 

 fuel. Its merits are ease of propagation, rapid growth while young, 

 suitability for nearly all locations and soils, general good health and 

 comparative freedom from insect pests For the present I am inclined 

 to think the box elder is fairly entitled to rank as a leading variety for 

 Dakota planting. It is one of the few trees that nature has distributed 

 throughout the west, and we are as yet not sufficiently out of the pio- 

 neer stage to warrant discarding any tree that will grow as well as this 

 species. As the country becomes more thickly settled the box elder 

 will probably give place to a variety having more economic value. 



ASH. A number of correspondents have asked what is the species 

 of the native ash Fraxinus viridis (green ash) or Fraxinus Ameri- 

 cana (white ash). My first thought was that ours is the white ash, 

 but in looking up the authorities, I find the weight of testimony favors 

 naming it the green ash. Dr. Sargeant places us beyond the range of 

 the F. Americana, which all botanists agree is the larger and better 

 tree. It is quite impossible to give characteristics that will enable 

 the amateur to distinguish between young trees of the two species; 

 the only strong point of difference is in the size of the mature trees; 

 F. Americana attains a height of 90 to 125 feet and a diameter of 3 to 

 5 feet. F. viridis reaches a heigh th of 45 to 54 feet and diameter of 

 1J to 2 feet. Other points of difference noted by botanists are: In 

 the white ash the leaflets are slightly downy beneath, 7 to 9 in num- 

 ber, ovate pointed, but little toothed. In the green ash the leaflets 

 are smooth beneath, 5 to 9 in number, narrower than last, sharp 

 toothed margins. But in either variety may be found specimens that 

 approach so near to the description of the other that it is often very 

 difficult to determine the species. In the fruit of green ash the body 

 is more than half the entire length ; often the wing is but little longer 

 than the body; in white ash the body of the fruit is only from one- 

 third to one-half the length of the wing. These points are given to 

 aid the reader in determining between the two most valuable species 

 of the genus. 



