A group of deciduous, unarmed trees, sometimes shrubs, allied to the elms, consisting of fifty to sixty species, a small proportion only of which are hardy. They are found in S.E. Europe, the Near East, N. America, and China. Leaves alternate, mostly three-veined, and unequal-sided at the base. The nettle-trees have no beauty of flower, these being small and greenish; the flowers are unisexual, but both sexes occur on the same tree, the male or pollen-bearing ones a few together in a cluster near the base of the new growths; the seed-bearing or female flowers solitary, or two or three together in the axils of the young leaves. Fruit a drupe, solitary on a slender stalk, one-seeded. The fruit affords the best distinction between the nettle-trees and the elms, the latter having dry, winged fruits.
As garden trees the species of Celtis make elegant and shapely specimens, yet of no particular merit or beauty, except that the leaves of several of them turn bright yellow in autumn. In warmer countries the timber is valuable, especially that of C. australis. The fruit of this species is sweet, and is said to have been the lotus of the ancients – that delicious fruit which constituted the food of the Lotophagi, and made those who ate it forget their own country (Treasury of Botany, i., p. 245). Other species have fruits edible in their native countries.
The nettle-trees like a good loamy soil and a well-drained position. They are best propagated by seeds, but when these are not obtainable grafting on stocks of C. occidentalis must be resorted to. Seeds of this species, if they do not ripen here, are always obtainable from American seedsmen.
There is little to distinguish the different cultivated species in a general way, except the leaves. Of those here dealt with, C. glabrata and C. bungeana are distinct in having no down on the leaves; C. laevigata is the only one with uniformly or nearly uniformly entire leaves; and C. australis has lanceolate, very downy leaves.