Genus PLANER A, Gmel. 



[Jlmaceae. Polygamia Monoecia j or Tetr-Pent-andria Digynia. 



Syst. ycil. Hi/sl. Lin. 



Synonymcs. 

 Flanera, ZUmus, Shamnus, Of Authors. 



Derivation. The <;enu3 Planera was so named in honour of Johann Jakob Planer, profesaor of botany at Erfurth, who pub 

 lished, in 17S8, a worlc ealilled " Plaularum Agri Erfordiensis," in one volume, tivo. 



Generic Characters. Sexes polygamous, or each in a distinct flower ; in each case upon the same plant. 

 Calyx of female and bisexual flowers bell-shaped, distinct from the ovary, membranous, green, of one 

 piece, but having 5 ciliate lobes. Stamens, in the bisexual flower, 4 5, less developed than those in 

 the male flower. Ovary top-shaped, villous. Stigmas 2, sessile, diverging, white, pimpled. Fruit 

 roundish, gibbous, pointed, dry, 2-celled, each cell containing 1-seed. Calyx of male flower as in the 

 female and bisexual flowers. Stamens 4 5, inserted near the centre of the bottom of the calyx, and 

 opposite to its lobes. Anthers reaching a little beyond the lobes of the calyx, borne outwardly to the 

 filament, of 2 lobes that seem as 4, and 2 cells that open sidewise and lengthwise. In P. gmelini, (P. 

 ulmiiblia.) the fruits are in heads ; and in P. richardii, nearly solitary. Leaves alternate, and more 

 or less ovate and toothed ; feather-veined and annual ; and the flowers, small, and not showy. P. rich- 

 ardii has stipules, which are straight, pointed, villous, and soon fall ofi". Adapted, from Turpin, Mi- 

 chaux, and Loudon. 



|HE genus Planera embraces deciduous trees and shrubs, natives of 

 western Asia, and of North America ; quite hardy in Britain, and 

 in the middle states of the American union, and are readily propa- 

 gated by grafting on the elm, by layers, and cuttings of the roots, 

 or from seeds, in any common soil. There are at least two spe- 

 cies in this genus, the zelkoua-tree, (Planera richardii,) and 

 Gmelin's planera (Planera ulmifolia.) The former is a beautiful lofty tree, 

 growing to a height of seventy or eighty feet, native of the country between the 

 Black and Caspian Seas, particularly of Imiretta and Mingrelia ; also of the north 

 of Persia, and of Georgia. It is distinguished by its shining-green, broadly 

 crenulated leaves, its smooth, greenish trunk, and somewhat resembles the 

 beech, except that its branches are more numerous, and grow more erect. Both 

 the sap-wood and the heart-wood of the zelkoua are employed as timber for the 

 same purposes as the oak. The heart-wood, when cut obliquely, resembles that 

 of the robinia, and like that wood, presents numeroi;s interlacements of fibre. 

 It is very heavy, and when dry, becomes so extremely hard, that it is difficult 

 to penetrate it with nails. It has, also, the great advantage of never becoming 

 worm-eaten, however old it may be. It is remarkably durable as posts, to stand 

 either in water or in the earth. The largest recorded tree of this species, in Eu- 

 rope, is on the estate of M. le Compte de Dijon, at Podenas, near Nerac, in 

 France, fh the department of the Lot et Garonne. It was planted in 1789; and 

 on the 29th of January, 1831, it measured nearly eighty feet in height, with a 

 trunk three feet in diameter, at a yard above the ground. The Planera richardii 

 was first introduced into Britain in about the year 1760, and planted in the gar- 

 dens at iSyon and at Kew, in which there are specimens exceeding fifty feet in 

 height. The zelkoua or zelkona, was introduced into the United States in 1784, 

 by the late William Hamilton, at the Woodlands, near Philadelphia, where there 

 are five beautiful fasti giate-gro wing trees, from forty-five to fifty or more feet in 

 height, with trunks from eighteen inches to two feet in diameter. 



