Some of the American species of hackberry are very variable. The habitat of the species varies from deep swamps to arid rocky slopes. In fact, a single species as now understood may have a variable habitat. The following variations may be noted on the same tree or on different trees of the same species. The twigs may be glabrous, or pubescent; the leaves may vary in size, shape and texture, leaf margin, and in the roughness or smoothness of the surfaces; the petioles may be smooth or hairy; the pedicels may be glabrous or pubescent, shorter or longer than the petioles; the fruit also varies in shape. Leaves have been seen on the same tree which were smooth above, while others were quite rough above, the difference being due to the exposure to light. The original descriptions of the species are too short to sufficiently characterize the species, which adds to the confusion. However, C. S. Sargent[45] has recently revised the species and varieties of our area. Prof. Sargent has examined and named all of my material for me. Mr. B. F. Bush, who has extensively studied the hackberries in the field, also has examined my specimens. The writer has paid special attention to the hackberries of the State for the past few years and is still in doubt as to the status of the species that occur in the State. Since I am not following the determinations made by Sargent and Bush, and am following the nomenclature of the first edition, I regard the present treatment as tentative only. Margins of all the leaves sharply serrate all around except at base; nutlets 6-8 mm. long 1 C. occidentalis. Margins of leaves of fruiting branches generally entire, or some with a few teeth on one side or with a few teeth on both sides; margins of the leaves of vegetative branches and shoots similar to those of fruiting branches or with the margins serrate nearly all around; nutlets 5-6 mm. long. Leaves of a rather broad ovate type; mature fruit a dark cherry-red; usually shrubs, sometimes very small trees, of a dry habitat 2 C. pumila. Leaves of an ovate-lanceolate type; mature fruit a light cherry-red; medium-sized trees of a wet habitat 3 C. mississippiensis. [Illustration: Plate 61. CELTIS OCCIDENTALIS Linnæus. Hackberry. (x 1/2.)]