34t) URTICACEAE (^NETTLE FAMILY) 



doubly serrate (5-10 cm. long), soft-pubescent beneath or soon glabrate ; flowers 

 in close fascicles ; calyx with 7-9 roundish lobes ; fruit glabrous except the 

 margins (1.2 cm. long), its sharp points incurved and closing the notch. — Moist 

 woods, especially along rivers, in rich soil. Apr. — A large and well-known 

 ornamental tree, variable in habit, usually with spreading branches and droop- 

 ing branchlets. 



4. U. racembsa Thomas. (Cork or Rock E.) Bud-scales doiony-ciliate smd 

 somewhat pubescent, as are the young branchlets ; branches often with corky 

 ridges ; leaves nearly as in the last, but with veins more simple and straight ; 

 flowers racemed ; fruit much as in the last, but rather larger. ( U. Thomasi 

 Sarg.) — River-banks and calcareous ridges, w. Que. and w. Vt. to Ont. and 

 Minn., s. to Mo. and Ky. — A large and very valuable tree. 



5. U. alata Michx. (Wahoo or Wixged E.) Bud-scales and branchlets 

 nearly glabrous; branches^ at least some of them, corky-winged \ leaves downy 

 beneath, ovate-oblong and oblong-lanceolate, acute, thickish, small (3-6 cm. long); 

 calyx-lobes obovate ; fruit downy on the face when young. — Va. to s. Ind., s. 

 Mo., and southw. Mar. — A small tree. 



•I- -t- Flowers autumnal^ appearing long after the leaves. 



6. U. ser5tina Sarg. Tree of moderate size ; leaves narrowly obovate, acumi- 

 nate, doubly serrate, paler and soft-pubescent beneath ; flowers racemose ; calyx 

 cleft nearly to the base, its divisions very narrow ; fruit rhombic-ovate, 2-horned, 

 5 mm. broad. — Limestone hills and bottoms, s. Ky. to n. Ala. and Ga. 



2. PLANERA J. F. Gmel. Planer Tree 



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

 ovoid, 1-celled, 1-ovuled, with"2 spreading styles which are stigmatose down the 

 inner side, in fruit becoming coriaceous. — Trees with small leaves, like those of 

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

 J. J. Planer, 1743-1789, a German botanist and professor at Erfurt.) 



1. P. aquatica (Walt.) J. F. Gmel. (Water Elm.) Nearly glabrous; 

 leaves ovate-oblong, small ; fruit stalked in the calyx, beset with irregular rough 

 projections. — Coastal swamps, N. C. to Fla. and Tex. ; inland in the Miss, basin 

 to Mo. , s. 111. and Ky. Apr. — A rather small tree. 



3. CELTIS [Tourn.] L. Nettle-tree. Hackberry 



Calyx 5-6-parted, persistent. Stamens 5-6. Ovary 1-celled, with a single 

 suspended ovule ; stigmas 2, long and pointed, recurved. Cotyledons folded 

 and crumpled. — Flowers greenish, axillary, the fertile solitary or in pairs, 

 peduncled, appearing with the leaves, the lower usually staminate only, fascicled 

 or racemose along the base of the branches of the season. (A name of Pliny's 

 for an African species of Lotus, transferred to this genus perhaps on account 

 of the sweet berries) . 



1. C. occidentalis L. (Sugarberry.) Leaves reticulated, ovate, cordate- 

 ovate and ovate-lanceolate, taper-pointed, usually conspicuously and sharply so, 

 more or less oblique at base, sharply serrate, sometimes sparingly so or only 

 toward the apex, scabrous but mostly glabrous above, usually soft-pubescent 

 beneath, at least when young ; fruit reddish or yellowish, turning dark purple at 

 maturity, its peduncle once or twice the length of the petiole. (O. canina Raf.) 



— Woods and river-banks, w. Que. and N. E. to Man., and southw. Apr., May. 



— A small or sometimes large tree, with the aspect of an Elm, bearing sweet and 

 edible fruits as large as bird-cherri.*s, at first obovoid, ripe in autumn ; the flesh 

 thin. Variation as to stature, foliage, form and color of fruit, etc., great in 

 extent but withomt clear correlation. Var. ptJMiLA Muhl. is a dwarf form, being 

 merely a low straggling shrub. Var. crassif6lia (Lam.) Gray is a tree and 

 may often be distinguished by its pubescent branchlets and large (9-13 cm. 

 long) commonly cordate leaves scabrous on the upper surface. 



2. C. mississippi6nsis Bosc. Leaves entire (rarely few-toothed), very long- 



