462 URTICACE.E. (nettle FAMILY.) 



9. Lraportea. Sepals 5 in the sterile flowers, 4 in the fertile, or a pi)arently only 2. Stigma 

 long-subulate. Achene very oblique, deflexed, nearly naked. Leaves alternate. 



4- -t- Plant wholly destitute of stinging bristles. Leaves opposite 



10. Pilea. Sepals 3 or 4, those of the fertile flowers unequal, all or all but one small 

 Achene partly naked, straight and erect. Stigma pencil-tufted. Smooth and shining. 



* * Fertile calyx tubular or cup-shaped, enclosing the achene. Unarmed. 



IL Boeliuieria* Flower-clusters spiked, not iuvolucrate. Style long and thread-shaped, 

 stigiuatic down one side. Leaves opposite, serrate. 



12. Parietaria. Flowers in involucrate-bracted clusters. Stigma tufted. Leaves alter- 

 nate, entire. 



1. ULMUS, L. Elm. 



Calyx bell-shaped, 4-9-cleft. Stamens 4-9, with long aud slender fila- 

 ments. Ovary 1 - 2-celled, with a single auatropous ovule suspended from the 

 summit of each cell ; styles 2, short, diverging, stigmatic along the inner edge. 

 Fruit a 1-celled and 1-seeded membranaceous samara, winged all around. 

 Albumen none ; embryo straight ; the cotyledons large. — Flowers polyga- 

 mous, purplish or yellowish, in lateral clusters, in our species preceding the 

 leaves, which are strongly straight-veined, short-petioled, aud ol)lique or un- 

 equally somewhat heart-shaped at base. Stipules small, caducous. (Ihe 

 classical Latin name.) 



* Flowers nearli/ sessile ; fruit orbicular, not ciliate ; leaves very rough above. 



1. U. flilva, Michx. (Slippery or Red Elm.) Buds before expansion 

 soft-downy with rusty hairs (large) ; leaves ovate-oblong, taper-pointed, doubly 

 serrate (4 -8' long, sweet-scented in drying), soft-downy beneath or slightly 

 rough downward; branchlets downy; calyx-lobes aud stamens .ti-9; fruit 

 (8-9" wide) with the cell pubescent. — Rich soil, X. Eng. to the Dakotas, and 

 southward. March, April. — A small or middle-sized tree (45-60° high), with 

 tough, reddish wood, and a very mucilaginous inner bark. 



* * Floivers on slender drooping pedicels, which are jointed above the middle ; 

 fruit ovate or oval, f ring ed-ciliate ; leaves smooth above, or nearhj so. 



2. U. Americana, L. (American or White Elm.) Buds and branch- 

 lets glabrous ; branches not cork// ; leaves obovate-oblong or oval, abruptly 

 pointed, sharply and often doubly serrate (2 - 4' long), soft-pubescent beneath, 

 or soon glabrous ; flowers in close fascicles ; calyx with 7-9 roundish lobes; 

 fruit glabrous except the margins (J' long), its sharp points incurved and clos- 

 ing the notch. — Moist woods, especially along rivers, in rich soil. April. — A 

 large aud Avell-known ornamental tree, variable in habit, usually with spread- 

 ing branches and drooping branchlets. 



3. U. raeemosa, Thomas. (Cork or Rock Elm.) Bud-scales downij- 

 ciliate and somewhat pubescent, as are the young branchlets ; branches often 

 ivith cork 11 ridges ; leaves nearly as in the last, but witli veins more simple and 

 straight ; flowers racemed ; fruit much as in the last, but rather larger. — River- 

 banks, S. W. Vt. to Out. and central Minn., south to ]\Io. and Ky. A large 

 and very valuable tree. 



4. IJ. alata, Michx. (Wahoo or Wixged Elm.) Bud-scales and branch- 

 Jets nearli/ glabro}is ; branches corkij-ivinged, at least some of them; leaves 

 downy beneath, ovate-oblong and oblong-lanceolate, acute, thickish, small 



