Trees of Neiv York S^fate 203 



ULMACEAE 



Ulmus americana L. 



White Elm, American Elm 



Habit — The largest of the elms. A tree usually 60-100 feet in height with a 

 trunk diameter of 2-5 feet, under optimum conditions sometimes 140 feet 

 tall \\-ith a crown spread of 50-70 feet. In the open the cro^\^l is very 

 variable. Well known varieties are the vase form, the umbrella form and 

 the feathered form. Bole tall and straight, bearing a high crown of grace- 

 ful, drooping branches, or short and often buttressed at the base and soon 

 breaking up into large, ascending limbs. 



Leaves — Alternate, oval to obovate-oblong, 4-6 inches long, 1-3 inches wide, 

 acuminate at the apex, rounded and inequilateral at the base, coarsely 

 doubly serrate, at maturity dark green and glabrate and slightly scabrous 

 above, paler and soft pubescent or quite glabrous below, with prominent 

 midrib and parallel secondary veins, borne on stout petioles about V^ of an 

 inch long. 



Plowers — Perfect, pedicellate, appearing before the leaves during April and 

 May in long pedunculate, 3-4 flowered inflorescences from the axils of the 

 inner scales of separate flower-buds, each bud giving rise to 5-8 fascicles. 

 Calyx campanulate, reddish green, puberulous, 7-9-lobed, the lobes short, 

 rounded and ciliate on the margins. Stamens as many as the corolla lobes, 

 exserted, with slender filaments and red anthers. Pistil with light greeji, 

 compressed. 2-celled ovary surmounted by 2 green styles white papillate 

 along the inner surface. 



Fmit — A 1-seeded, oval to obovate-oblong, long-stalked, pale green samara. 

 about Vq of an inch long, marked b,y a horizontal line indicating the union 

 of the 2 carpels, smooth aside from the ciliate margin, ripening :if the 

 leaf-buds begin to imfold. Wing reticulate-venulose, ciliate on the mar- 

 gin, deeply notched at the apex, the teeth incurved and overlapping. 



Winter characters— - Twig slender, Itnticellate, glabrous or puberulous, ligh.t 

 reddish brown, at length dark brown or ashy-gray. Terminal bud absent. 

 Leaf-buds ovate, acute, chestnut-brown, about % of an inch long. Flower- 

 buds slightly larger, borne below- the leaf-buds. Mature bark thick, 

 rough, ashy-gray, irregularly divided by deep fissures into broad, scaly 

 ridges. 



Habitat — Typically a bottom-land species, preferring moist, rich alluvial 

 soils along stream courses and lakes but thriving well on upland sites, 

 usually in admixture with other species. Not exacting as to soil recjuire- 

 ments. 



Bange — Xewf oundland west through southern Canada to the eastern slopes 

 of the Kocky Mountains, south to Florida and eastern Texas. The most 

 widely distributed of the American elms. Zones B, C, and D. 



Uses — A valuable species. Wood heavy, hard, strong, coarse-grained, tough, 

 diflicult to split, light brown Avith wide, paler sapwood. Widely used for 

 cheese boxes, cooperage, and a variety of purposes including planking, 

 wheel hubs. etc. The tree with its various forms is valuable as a shade 

 and ornamental species along avenues and highways. 



