396 dkticacejE. (nettle family.) 



rough downwards; branchlets downy; calyx-lobes and stamens "-9; fruit 

 (i'-3' wide) with the cell pubescent. — Along streams, common from W. New 

 England to Wisconsin and Kentucky. March, April. — A small or middle- 

 sized tree, with tough reddish wood, and a very mucilaginous inner bark. 

 * * Flowers on slender drooping peduncles or pedicels, which are jointed above the 



middle : fruit ovate or oval, fringed-ciliate : leaves smooth and glabrous above, or 



nearly so. 



2. U. Americana, L. (pi. Clayt.), "Willd. (Ambkican or White 

 Elm. ) Buds and branchlets glabrous ; branches not corky ; leaves obovate-oblong 

 or oval, abruptly pointed, sharply and often doubly sen-ate (2' -4' long), soft- 

 pubescent beneath, or soon glabrous; flowers in dose fascicles ; calyx with 7-9 

 roundish lobes ; fruit glabrous except the margins [^' long), its shai-p points in- 

 curved and closing the notch. — Moist woods, especially along rivere, in rich 

 soil ; common. April. — A large and well-known ornamental tree, with spread- 

 ing branches and drooping branchlets. 



3. v. racemosa, Thomas. (Cokkt White Elm.) Bud-scales downy- 

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

 corky ridges; leaves nearly as in the last; flowers racemed; fi-uit much as in the 

 last, but rather larger. — River-banks, W. New England, New York, and Mich- 

 igan. April. — Wood tougher and finer-grained than in the last. 



4. U. aiata, Michx. (Winged Elm, Whahoo.) Bud-scales and 

 branchlets nearly glabrous ; brandies corhy-winged, at least some of them ; leaves 

 ovate-oblong and oblong-lanceolate, acute, thickish, small (!'- 2j' long), seldom 

 oblique ; calyx-lobes obovate ; fruit downy on the face, at least when young. — 

 Virginia, Kentucky, and southward. March. — Wood fine-grained, valuable. 



U. CAMPi:STEis, L., the English Elm, was early introduced near Boston, 

 &c. 



2. PI^AlVERA, Gmel. Planee-Tbee. 



Flowers monceciously polygamous. Calyx 4 - 5-cleft. Stamens 4 -5. Ovary 

 ovoid, l-celled, 1-ovuled, crowned with 2 spreading styles which are stigmatose 

 down the inner side, in fruit becoming coriaceous and nut-like, not winged. 

 Albumen none : embryo straight. — Trees with small leaves, like those of Elms, 

 the flowers appearing with them, in small axillary clusters. (Named for J. J. 

 Plana-, a German botanist.) 



1 . P. aqii&tica, Gmel. Nearly glabrous ; leaves ovate-oblong, small ; 

 fruit stalked in the calyx, beset with irregular rough projections. — Wet banks, 

 Kentucky (Michx.) and southward. April. 



3. CEIiTIS, Tonm. Nettle-teee. Hackbeeet. 



Flowers monceciously polygamous. Calyx 5 - 6-parted, pereistent. Stamens 

 5-6. Ovary l-celled, with a single suspended ovule : stigmas 2, long and 

 pointed, recurved. Fruit a globular drape. Embryo curved, nearly enclosing 

 a little gelatinous albumen : cotyledons folded and crumpled. — Leaves pointed, 

 petioled. Stipules caducous. Flowers greenish, axillary, the fertile solitary or 



