33^ FLORA. 



natives of the northern nemisphere. Besides the following, 3 others occur in the 

 southern U. S. and one in Mex. 



Leaves smooth or slightly rough above; samara densely ciliate. 



None of the branches corky-winged; samara-faces glabrous. 1. U. Americana. 



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



Leaves 5-13 cm. long; flowers racemose; northern. 2. U. racemosa. 



Leaves 2-8 cm. long; flowers fascicled; southern. 3. U.aiata. 



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



1. Ulmus Americana L. American White or Water Elm. (I. F. f. 1250.) 

 A large tree, with gray flaky bark, and glabrous or sparingly pubescent twigs and 

 buds, the branches terete. Leaves oval or obovate, apex abruptly acuminate, ba^c 

 obtuse or obtusish, and very inequilateral, sharply and usually doubly serrate, 

 slightly rough above, 5-13 cm. long; flowers fascicled ; pedicels filiform, drooping, 

 jointed ; calyx 7-9-lobed, oblique, its lobes oblong, rounded ; samara ovate -oval, 

 reticulate-veined, 10-12 mm. long, its faces glabrous; styles strongly incurved, in 

 moist soil, especially along streams, Newf. to Manitoba, Fla. and Tex. March-April. 



2. Ulmus racemosa Thomas. Cork or Rock Elm. (I. F. f. 125 1.) A 

 large tree, the young twigs puberulent; bud-scales ciliate and somewhat pubescent; 

 branches, or some of them, winged by narrow plates of cork. Leaves similar to 

 those of the preceding, but less sharply serrate, smooth above ; flowers racemose ; 

 pedicels filiform, drooping, jointed ; calyx-lobes oblong, rounded ; samara oval, 

 12-16 mm. long, its margins densely ciliate; persistent styles strongly incurved and 

 overlapping. In rich soil, Quebec to Ont., Mich., N. J., Tenn. and Neb. April. 



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

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



3. Ulmus alata Michx. Winged Elm. Wahoo. (I. F. f. 1252.) A small 

 tree, the branches, or most of them, with corky wing-like ridges. Twigs and buds 

 glabrous or nearly so; leaves oblong, oblong-lanceolate or oblong-ovate, acute, 

 doubly serrate, base obtuse, inequilateral and sometimes subcordate, roughish above, 

 pubescent beneath, at least on the veins, 2-8 cm. long; flowers fascicled; pedicels 

 filiform; calyx-lobes obovate, rounded; samara oblong, 8-10 mm. Jong, pubescent 

 on the faces; styles very slender. In dry or moist soil, S. Va. to Fla., 111., Ark. 

 and Tex. March. 



4. Ulmus fulva Michx. Slippery. Red or Moose Elm. (I. F. f. 1253.) 

 A tree, with rough gray fragrant bark, twigs rough-pubescent; bud-scales densely 

 brown tomentose. Leaves ovate, oval or obovate, very rough with short papillae 

 above, pubescent beneath, sharply doubly serrate, acuminate at the apex, obtuse, 

 inequilateral and commonly cordate at the base, 1-2 dm. long; flowers fascicled; 

 pedicels 4-6 mm. long, spreading, jointed near the base; calyx-lobes lanceolate, 

 subacute, samara oval orbicular, 12-18 mm. long, pubescent over the seed. In 

 woods, on hills and along streams, Quebec to N. Dak., Fla. and Tex. March- 

 April. 



2. PLANERA J. F. Gmel. 



Trees, similar to the elms, the flowers monoecious or polygamous, unfolding 

 with the leaves. Staminate flowers fascicled on twigs of the preceding season, the 

 pistillate or perfect ones in the axils of leaves of the year. Calyx 4-5 cleft, cam- 

 panulate. persistent, the lobes imbricated. Filaments filiform, straight, exserted. 

 Ovary stalked, ovoid, slightly compressed, 1 -celled. Styles 2, spreading, stigmatic 

 along the inner side. Fruit coriaceous, obliquely ovoid, compressed, ridged on the 

 back, covered with short fleshy processes. Embryo straight. [Name in honor of 

 Johann Jakob Planer, 1743-1789, Professor of Botany in Erfurt.] A monotypic 

 genus of southeastern N. Am. 



1. Planera aquatica (Walt.) J. F. Gmel. Planer-tree. Water Elm. 

 (I. F. f. 1254.) A small tree, the foliage nearly glabrous. Leaves ovate or 

 oblong -lanceolate, acute at the apex, obtuse or cordate and usually somewhat 

 inequilateral at the base, serrate, 3-4 mm. long; petioles 2-5 cm. long; stipules 

 lanceolate, about as long as the petioles, deciduous; -taminate flowers fascicled 

 and somewhat racemose from scaly buds, perfect or pistillate flowers on short 



