120 Eleventh Annual Report 



Economic uses. Too rare to be of any economic use. 



Horticultural value. Adapted to a moist soil, in which it grows 

 very rapidly. Propagated either by cuttings or seedlings. It is 

 used as a windbreak and is frequently planted for ornamental pur- 

 poses. 



2. POPULUS. The Poplars. 



(From the Latin, populus the people; the trees used by the ancients along the highways.) 



Rapidly growing trees; buds large, scaly and more or less resin- 

 ous; leaves alternate, broad, toothed or sometimes lobed; flowers 

 on pendulous catkins; anthers purple-red. 



In the following key mature leaves from trees are considered : 



Winter buds cottony, leaves more or less lobed IP. alba. 



Winter buds not cottony, leaves with margins more or 

 less regularly toothed. 

 Winter buds pubescent, appearing dusty; margins of 



leaves with 5 or less teeth per 25 mm. (1 inch) .... 2 P. grandidentata. 

 Winter buds glabrous or nearly so; margins of leaves 

 with 6 or more teeth per 25 mm. (1 inch). 

 Leaf blades blunt or rounded at the apex; shoots at 



first hoary becoming glabrous and brown 3 P. heterophylla. 



Leaf blades sharp pointed at the apex; shoots smooth 

 or with only a few hairs, becoming gray. 

 Apex of most of the leaves without teeth for about 

 5 mm. (3^ inch); winter buds resinous and 

 sticky, about 8 mm. (}i inch) long; stamens 



less than 15 4 P. tremuloides. 



Apex of most of the leaves without teeth for about 

 10 mm. (3^ inch); winter buds resinous but 

 dry, about 12 mm. (3^ inch) long; stamens 

 more than 15 5 P. deltoides. 



1. Populus alba Linnaeus. Silver-leaf Poplar. Plate 19. 

 Bark on young trees smooth, greenish-white or gray, on old trees 

 furrowed, gray or dark brown; young twigs hairy, becoming smooth 

 in age; leaves ovate or triangular, 3-5 lobed or occasionally irregu- 

 larly toothed, hairy on both surfaces while expanding, becoming 

 dark green and glabrous above and remaining white-hairy beneath; 

 stamens usually less than 15, flowering season, March, April or 

 May. 



Distribution. Introduced from Europe, now frequent in all parts 

 of the State. 



