TREES OF NORTH AMERICA 



base, scarious, inclosing the leaf in the bud, caducous. Flowers from axillary buds 

 near the ends of the branches similar to but larger than the leaf-buds, the outer 

 scales sterile, the inner bearing flowers and rarely leaves. Flowers perfect, jointed 

 on slender bibracteolate pedicels from the axils of linear acute scarious bracts, in 

 pedunculate or subsessile fascicles or cymes, appearing in early spring before the 

 leaves in the axils of those of the previous year, or autumnal in the axils of leaves 

 of the year; calyx carnpanulate, 5-9-lobed, membranaceous, marcescent; stamens 

 5 or 6 inserted under the ovary; filaments filiform or slightly flattened, erect in the 

 bud, becoming exserted; anthers oblong, emarginate, and subcordate; ovary sessile 

 or stipitate, compressed, crowned by a simple deeply 2-lobed style, the spreading 

 lobes papillo-stigmatic on the inner face, usually 1-celled by abortion, rarely 2-celled; 

 ovule amphitropous; micropyle extrorse, superior. Fruit an ovate or oblong, often 

 oblique, sessile or stipitate samara surrounded at the base by the remnants of the 

 calyx, membranaceous, the seminal cavity compressed, slightly thickened on the 

 margin, chartaceous, produced into a thin reticulate-venulose membranaceous light 

 brown broad or rarely narrow wing naked or ciliate on the margin, tipped with the 

 remnants of the persistent style, or more or less deeply notched at the apex, and 

 often marked horizontally by the thickened line of the union of the two carpels. 

 Seed ovate, compressed, without albumen, marked on the ventral edge by the thin 

 raphe; testa membranaceous, light or dark chestnut-brown, of two coats, rarely pro- 

 duced into a narrow wing; embryo erect ; cotyledons flat or slightly convex, much 

 longer than the superior radicle turned toward the oblong linear pale hilum. 



Ulmus, with fifteen or sixteen species, is widely distributed through the boreal 

 and temperate regions of the northern hemisphere with the exception of western 

 North America, reaching in the New World the mountains of southern Mexico and 

 in the Old World the Sikkim Himalaya, northern China, and Japan. Of the exotic 

 species, Ulmiis campestris, L., and Ulmus glabra, Huds., have been largely planted for 

 shade and ornament in the north Atlantic states, where old and large specimens of 

 the former can be seen, especially in the neighborhood of Boston. 



Ulmus produces heavy, hard, tough, light-colored wood, often difficult to split. 

 The tough inner bark of some of the species is made into ropes or woven into 

 coarse cloth, and in northern China nourishing mucilaginous food is prepared from 

 the inner bark. 



Ulmus is the classical name of the Elm-tree. 



CONSPECTUS OF THE NORTH AMERICAN SPECIES. 



Flowers vernal, appearing before the leaves. 



Flowers on slender drooping- pedicels ; fruit ciliate on the margins. 

 Wing of the fruit broad. 



Bud-scales and fruit glabrous ; branchlets destitute of corky wings ; leaves obovate- 

 oblong to oval, usually smooth on the upper, soft-pubescent on the lower surface. 



1. U. Americana (A, C). 



Bud-scales puberulous ; branches often furnished with corky wings ; fruit hirsute ; 

 leaves obovate to oblong-oval, smooth on the upper, soft-pubescent on the lower 

 surface. 2. U. Thomasi (A). 



Wing of the fruit narrow. 



Bud-scales glabrous or slightly puberulous ; branchlets furnished with broad corky 

 wings; fruit hirsute, stipitate ; leaves ovate-oblong to oblong-lanceolate, smooth 

 on the upper, soft-pubescent on the lower surface. 3. U. alata (A, C). 



