240 



Lea^'es not yellow green beneath; base of the petiole of the 



terminal lea^^es not enlarged, petioles smooth, or if 



pubescent at the base the pubescence will be more or 



less evident the entire length of the petiole. 



Petioles smooth; leaves 3-5 lobed, blade as long or 



longer than wide, not densely pubescent beneath 



at maturity 5 A. saccharum. 



Petioles smooth; lea^'es 3-lobed, blades wdder than 



long A. saccharum var. 



Riigelii. 

 Petioles pubescent, rarely smooth; leaves 5-lobed, 

 rarel;\' 3-lobed, the under surface densely pubescent 



at maturity A. saccharum var. 



Schneckii. 



1. Acer Negi'indo Linnaeus. Box Elder. Plate 111. A medium - 

 sized tree with a short trunk and round head; Vjark of young trees 

 smooth and gray, becoming thick on old trees, light to dark brown 

 and more or less furrowed or rarely somewhat flaky; twigs smooth and 

 greenish; leaves of average size are 1.5-3 dm. long, generally with 3 

 leaflets on the flowering branches, sometimes 5 or rarel3^ with 7, on 

 sterile branches or on growing shoots 3-7, the petioles generally \^- 

 ]2 the length of the leaf and glabrous or nearly so at maturity; leaf- 

 lets all on stalks more or less pubescent, the lateral stalks short, the 

 terminal ones much longer, leaflets of var jdng size and shape, the margins 

 usually varying from lobed to serrate or entire, pinnatelj^ veined, 

 smooth above at maturity and remaining more or less pubescent be- 

 neath, especially along the veins; flowers appear just before the leaves 

 the last of April or the first of May, the staminate and pistillate on 

 sepai'ate trees; fruit matures late in summer, the body of the samara 

 green and more or less pubescent. 



Distribution. — New England to Florida, west to Minnesota and 

 south to eastern Texas. In Indiana, it is found throughout the State in 

 moist or wet places along creeks and rivers, and infrequently on the 

 highlands along roadsides and fences. Its original distribution in the 

 State can only be conjectured. Judging from its tolerance to shade and 

 its habitat, and from the earliest reports of its occurrence in the State, 

 this species was cjuite rare in the northern part of the State, becoming 

 infrequent to frequent in its habitat in the southern part of the State. 

 Even today it is rather local in its distribution. I have never seen it on 

 the low mtu'ky border of a lake. 



Remarks. — This species on account of its rapid growth was formerly 

 mtich used in oui' area as a shade tree. It is believed that most of the 

 trees now found along roadsides, fences, clearings and on the drier 

 banks of streams are from seed distributed by the wind from ])lanted 



