524 



ULMACEAE. 



i. ULMUS L. Sp. PI. 225. 1753. 



Trees, with 2-ranked straight-veined inequilateral serrate leaves, with thin caducous 

 stipules-. Flowers perfect or polygamous, fascicled or racemose, greenish, unfolding before 

 the leaves, borne axillary on the twigs of the preceding season. Calyx campanulate, 4-9- 

 lobed, persistent, its lobes imbricated. Filaments erect, slender, exserted. Ovary sessile or 

 stalked, compressed. Styles 2, divergent, stigmatic along the inner margin. Fruit a i-seeded 

 flat orbicular or oval samara, its membranous wings continuous all around except at the 

 apex, commonly as broad as or broader than the body. Embryo straight. [The ancient 

 Latin name of the elm; Celtic elm.'} 



About 16 species, natives of the northern hemisphere, 

 in the southwestern United States and one in Mexico. 



Besides the following, another occurs 



Leaves smooth or slightly rough above; samara densely ciliate. 



None of the branches corky- winged ; samara- faces glabrous. i. U.Americana. 

 Some or all of the branches corky-winged; samara-faces pubescent. 



Leaves 2' -5' long; flowers racemose; northern. 2. U. racemosa. 



Leaves i'~3' long; flowers fascicled; southern. 3. U. alata. 



Leaves very rough above ; samara not ciliate ; twigs not corky-winged. 4. L'.fulva. 



i. Ulmus Americana L. American, White or Water Elm. (Fig. 1250.) 



Ulmus Americana L. Sp. PI. 226. 1753. 



A large tree, with gray flaky bark, and glabrous 

 or sparingly pubescent twigs and buds; maximum 

 height about 120, and trunk diameter 11; the 

 branches not corky- winged, terete. Leaves oval or 

 obovate, apex abruptly acuminate, base obtuse or 

 obtusish, and very in equilateral, sharply and usually 

 doubly serrate, slightly rough above, pubescent or 

 becoming glabrous beneath, 2'-$' long, i)4'-3 r 

 wide; flowers fascicled; pedicels filiform, drooping, 

 jointed; calyx 7~9-lobed, oblique, its lobes oblong, 

 rounded; samara ovate-oval, reticulate-veined, 5 /r - 

 6" long, its faces glabrous, its margins densely cil- 

 iate; styles strongly incurved. 



In moist soil, especially along streams. Newfound- 

 land to Manitoba, Florida and Texas. Wood hard, 

 strong, close-grained, compact, dark brown; weight 

 per cubic foot 40.5 Ibs. March-April. Samaras ripe 

 in May. 



2. Ulmus racemosa Thomas. Cork or Rock Elm. 



L'lmtis racemosa Thomas, Am. Journ. Sci. 19: 170. 1831. 



A large tree, attaining a maximum height of 

 about 100 and a trunk diameter of 4, the young 

 twigs puberulent; bud-scales ciliate and somewhat 

 pubescent; branches, or some of them, winged by 

 narrow plates of cork. Leaves similar to the pre- 

 ceding, but less sharply serrate, smooth above; 

 flowers racemose; pedicels filiform, drooping, 

 jointed; calyx-lobes oblong, rounded; samara oval, 

 6"-8" long, its faces pubescent or puberulent, its 

 margins densely ciliate; persistent styles strongly 

 incurved and overlapping. 



In rich soil, Quebec to Ontario, Michigan, Tennessee 

 and Nebraska. Wood hard, strong, tough, compact; 

 color light reddish-brown; weight per cubic foot 45 Ibs. 

 April. Called also Cliff, Hickory or Swamp Elm. 



Ulmus campestris L., from Europe, distinguished by 

 its nearly or quite glabrous, not ciliate samaras, and 

 wingless branches, rarely escapes from cultivation. 



(Fig. 1251.) 



