i88 



Forests and Trees 



The bark on old trees is grayish-brown, thick, rough and 

 scaly. On young trees it is light gray, thin and smooth. The 

 leaves are pinnately compound of three or five leaflets, the end 

 leaflet on a long petiole and the lateral ones short-stalked. 

 The leaflets may be either entire, cr more or less three-lobed. 



The staminate and pistillate flowers are on different trees 

 and open before the leaves. The staminate flowers are on long, 

 drooping, hairy pedicels, while the pistillate ones are in racemes 

 which lengthen as the fruit matures. The 

 fruit is a double samara. 



The wood is light, soft and of little 

 value except locally as fuel. The tree 

 has been much used throughout the 

 prairie for planting, for which it is in 

 some ways well suited. It grows rapidly 

 and its leaves come early, so that it fur- 

 nishes green foliage earlier than any other 

 native tree in its range. It is short-lived, 

 much given to forking, splits easily at the 

 forks, and is very liable to be attacked 

 by insects, particularly the green aphis. 

 When a bad attack of aphis occurs, a 

 sticky secretion from the insect, known as " honey dew," 

 smears the leaves and runs down the trunk or falls in drops to 

 the ground. This often causes a fungous growth on the bark, 

 making it black and unsightly. The leaves fall early, espe- 

 cially if infested with aphis, and thus what it gains in foliage 

 in the spring it loses in the fall. 



In spite of its defects, there is no reason why this should 

 not continue to be valuable for street or park planting, if mixed 

 with other species. Exclusive planting of this species, however, 

 tends to breed its enemies and should be avoided. 



The Manitoba maple occurs native along the valleys of 

 streams across the prairie past the western boundary of Saskatch- 



FIG. 43. Manitoba 

 Maple. 



