ACERACEJE 



635 



lateral spreading lobes, cordate, with a broad sinus usually more or less closed by 

 the approximation or imbrication of the basal lobes, covered below when they 



unfold with hoary tomentum and above with caducous pale hairs, and at maturity 

 thick and firm in texture, dull green on the upper surface, yellow-green and soft- 

 pubescent, particularly along the yellow veins on the lower surface, and 5'-6' across, 

 with drooping sides, turning bright clear yellow in the autumn ; their petioles stout, 

 tomentose or pubescent, sometimes becoming glabrous at maturity, usually pendent, 

 3'-5' long, much enlarged at the base, frequently nearly inclosing the buds, in fall- 

 ing leaving narrow scars almost encircling the branchlet, and furnished in their axils 

 with tufts of long pale hairs; stipules triangular and dentate or foliaceous, sessile or 

 stipitate, oblong, acute, tomentose or pubescent, sometimes slightly lobed, frequently 

 1^' long. Flowers yellow, about ^' long, on slender hairy pedicels 2^'-3' long, in 

 many-flowered nearly sessile umbel-like corymbs, the staminate and pistillate in 

 separate or in the same clusters on the same or on different trees; calyx broadly 

 campanulate, 5-lobed by the partial union of the sepals, pilose on the outer surface 

 near the base; corolla 0; stamens 7 or 8, with slender glabrous filaments, in the 

 staminate flower nearly twice as long as the calyx and in the pistillate flower shorter 

 than the calyx; ovary obtusely lobed, pale green, covered with long scattered hairs, 

 minute in the sterile flower. Fruit glabrous, with convergent or wide-spreading 

 wings '-!' long; seeds smooth, bright red-brown, \' long. 



A tree, sometimes 80 high, with a trunk frequently 3 in diameter, stout spread- 

 ing or often erect branches, and stout branchlets marked by oblong pale lenticels, 

 when they first appear orange-green and pilose, with scattered pale caducous hairs, 

 orange or orange-brown and lustrous during their first year, becoming dull pale gray- 

 brown the following season. Winter-buds sessile, ovate, acute, %' long, with dark 

 red-brown acute scales hoary-pubescent on the outer surface and often slightly ciliate 

 on the margins, and yellow puberulous inner scales, '-!' long at maturity. Bark of 

 young stems and of the branches thin, smooth, pale gray, becoming on old trunks 

 thick, deeply furrowed, and sometimes almost black. 



Distribution. Valley of the St. Lawrence River in the neighborhood of Mon- 

 treal, southward to the valley of Cold River, New Hampshire, through western Ver- 

 mont, and westward through northern New York, Ontario, the southern peninsula 

 of Michigan, Indiana, Illinois, and Iowa, to northeastern South Dakota, western 



