45 



Decatur (Deam); Fulton (Deam) ; Gibson (Schneck) ; Jackson (Deam); 

 Jay (Deam); Knox (Deam); Laporte (Deam); Pulaski (Deam); Sullivan 

 (Deam); Warren (Deam); Wayne (Deam). 



2. POPULUS. The Poplars. 



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

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

 appearing before the leaves on large pendulous catkins; anthers red or 

 purple. 



In the following key mature leaves from trees are considei'ed: 



Petioles round or channeled, scarcely or not at all flattened ' 



lateralis^ 

 Leaves chall-rv'-wliile tomentose beneath, some of them 



more or less lobed, blades 6-10 cm. long IP. alba. 



Lea^-es pubescent or whitish tomentose ^^■hile joung, ne\er 



lobed, blades 10-17 cm. long 2 P. hetcrophylla. 



Petioles strongly flattened laterally esijecially near the lilade. 



Winter buds more than 8 mm. in length, stamens more than 



20, capsules more than 3 mm. in diameter, leaves broadly 



deltoid, majority more than 8 cm. wide 3 P. deltoides 



Winter buds less than 8 mm. in length, stamens fewer than 

 20, capsules less than 3 mm. in diameter, leaves roundish 

 ovate, majoritj' less than 8 cm. wide. 

 Winter buds more or less pubescent, dull ; leaves general- 

 ly with less than 12 teeth to a side 4 P. grandidentata. 



Winter buds smooth or rarely some\^'hat pubescent, 



glossy; leaves with more than 12 teeth to a side .5 P. tremuloides. 



1. Populiis alba Linnaeus. Silver-leaf Poplar. Plate 15. Short- 

 trunked trees with a round top, up to a meter or more in diameter; 

 bark on young trees smooth, greenish-white or gray, becoming furrowed 

 on old trees, gray or dark brown; shoots white tomentose, becoming 

 smooth in age; leaves ovate or triangular, 3-5 lobed or irregularly toothed, 

 hairy on both surfaces on expanding, becoming dark green and glabrous 

 above, remaining white tomentose beneath; stamens about 8; wood 

 light, soft and weak. 



Distribution. — Introduced from Europe and escaped in all parts of 

 the State. 



Remarks. — This tree has long been under cultivation, and several 

 horticultural forms have been introduced. It is falling into disuse 

 on account of its habit of sending up root shoots. It adapts itself 

 to all kinds of soil, grows rapidl}^ transplants easily, stands pruning 

 well and has few insect or fungous enemies. 



