564 



TREES OF NORTH AMERICA 



late at apex, ridged on the dorsal edge with a thin narrow ridge, thin and slightly grooved 

 on the ventral edge. 



A tree 20-30 high, with a trunk 12'-18' in diameter, small erect branches and slender 

 unarmed branchlets light yellow-green and puberulous or pubescent when they first ap- 

 pear, usually becoming glabrous before the end of their first season, light orange-brown 

 during their first season and dark red-brown the following year; sometimes a shrub only a 

 few feet tall; usually growing with a single well-developed trunk; occasionally spreading by 

 suckers from the roots into small thickets. Winter-buds acute, i'-jj' long, with light chest- 

 nut-brown puberulous scales ciliate on the margins. Bark pale gray-brown, exfoliating in 

 large thin scales. 



Distribution. Hillsides and river-bottom lands; southern Indiana (near Columbus, 

 Bartholomew County, and Gordon Hills, Gibson County), through southern Illinois (Galla- 

 tin, Pope, Richland and Johnson Counties) to western Kentucky (Ballard and Hickman 

 Counties); through Missouri and Arkansas to eastern Oklahoma, western Louisiana and 

 eastern Texas to Wilson County (Southerland Springs) ; through eastern Louisiana (West 

 Feliciana and Tammany Parishes), and near Selma, Dallas County, Alabama. 



6. Primus tenuifolia Sarg. 



Leaves oblong to oblong-obovate or elliptic, gradually narrowed and acute or acuminate 

 and often abruptly long-pointed at apex, cuneate or often narrowed and rounded at base, 

 finely doubly serrate with teeth pointing to the apex of the leaf, at maturity thin, dark 

 yellow-green and sparingly covered above with short soft white hairs, paler and soft pubes- 



Fig. 518 



cent below, especially on the slender midrib, and 7 or 8 pairs of thin primary veins con- 

 nected by occasional cross veinlets, 3'-4' long and lj'-2' wide; petioles slender, pubescent, 

 becoming puberulous or nearly glabrous, glandular near the apex with 1-3 prominent dark 

 glands, or eglandular. Flowers |' in diameter, opening from the middle to the end of 

 March, on slender pedicels f ' |' long, furnished near the apex with a few long white hairs, 

 in 2-4-flowered sessile umbels; calyx-tube narrow-obconic, glabrous with the exception of 

 occasional long scattered white hairs near the base, the lobes narrow, entire, or minutely 

 dentate near the rounded apex, ciliate on the margins, pubescent on the outer surface, 

 densely villose on the inner surface, reflexed after anthesis; petals white, ovate-oblong, nar- 

 rowed and rounded at apex, crenulate above the middle, gradually narrowed below into a 



