626 



ULMACEAE. 



VOL. I. 



i. ULMUS (Tourn.) 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, mostly axillary on 

 the twigs of the preceding season. Calyx campanulate, 4-9-lobed, persistent, its lobes imbri- 

 cated. Filaments erect, slender, exserted. Ovary sessile or stalked, compressed, i-2-celled. 

 Styles 2, divergent, stigmatic along the inner margin, ovule I in each cavity of the ovary, 

 suspended, anatropous. 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 1 6 species, natives of the northern hemisphere. Besides the following two others occur 

 in the southern United States and one in Mexico. Type species: Ulmus campestris L. 



Flowers appearing in the spring long before the leaves. 



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'-$' long ; flowers racemose ; northern. 2. U. Thomasi. 



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



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



Flowers appearing in the autumn. 5. U. serotina. 



* ^*^s~*^f 



i. Ulmus americana L. American, White or 

 Water Elm. Fig. 1539. 



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 inequilateral, sharply and usually 

 doubly serrate, smooth or rough above, pubescent or 

 becoming glabrous beneath, 2' 5' long, ii'-3' wide ; 

 flowers fascicled; pedicels filiform, drooping, 

 jointed ; calyx 7-p-lobed, oblique, its lobes oblong, 

 rounded ; samara ovate-oval, reticulate-veined, 5"-6" 

 long, its faces glabrous, its margins densely ciliate; 

 styles strongly incurved. 



In moist soil, especially along streams, Newfoundland 

 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. The 

 species consists of many slightly differing races. Swamp- 

 or rock-elm. 



2. Ulmus Thomasi Sarg. Cork or Rock Elm. 

 Fig. 1540. 



Ulmus racemosa Thomas, Am. Journ. Sci. 19 : 170. 1831. 



Not Borckh. 

 Ulmus Thomasi Sargent, Silva 14: 102. 1902. 



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, Minnesota, Kentucky, 

 Missouri and Nebraska. Wood hard, strong, tough, com- 

 pact ; color light reddish-brown ; weight per cubic foot 45 

 Ibs. April. Called also Cliff-, hickory- or swamp-elm. 

 Racemed or corky white-elm. Wahoo. 



Ulmus campestris L., from Europe, distinguished by its nearly sessile flowers, nearly or quite 

 glabrous, not ciliate samaras, and wingless branches, rarely escapes from cultivation. 



