This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Celtis crassifolia Lam. Encycl. 4: 138. 1797.
A large tree, sometimes 1250 high and with a trunk diameter of 30 or more, with rough, usually corky-thickened bark, the young twigs pubescent. Leaves ovate to ovate-lanceolate, acute or short-acuminate, rather coarsely toothed, 3'-6' long, scabrous above, rough-pubescent, especially on the veins, beneath, the petioles rather short; drupes short-oblong or nearly globular, about 5" in diameter, on stalks 8"-12" long.
In rich soil, especially in river valleys, Massachusetts (?), New Jersey to Indiana, South Dakota, South Carolina and Colorado. April-May. Fruit ripe Aug.-Sept. Probably not specifically distinct from the preceding species.
Celtis mississippiensis Bosc, Diet. Agric. 10: 41. 1810.
A tree, reaching a maximum height of about 100°, the trunk up to 30 in diameter, the bark light gray, rough and warty. Leaves ovate or lanceolate, firm, shining, entire or with a few low sharp teeth, 3-nerved and prominently pin-nately veined, glabrous on both sides, long-acuminate at the apex, inequilateral and obtuse or sometimes cordate at the base, 1'-3' long, 1/2'-1 1/2' wide; peduncles mostly shorter than those of the preceding species; drupes globose, purple-black, 2 1/2"-3" in diameter.
In dry soil, Virginia to southern Illinois and Missouri, south to Florida and Texas. Bermuda. April. Fruit ripe July-Aug.
Celtis Smallii Beadle, of the southern United States, differs by sharply serrate leaves and ranges north to western Kentucky.
A shrub, or small tree, up to 300 high, the young twigs slender, pubescent becoming purple-brown and, glabrous. Leaves ovate, small, rarely over 2' long, firm when mature, acute or bluntish, serrate, or sometimes nearly or quite entire, the upper surface bright green, scabrous, the under side pubescent, at least on the veins; drupe globose, 3"-4" in diameter, red-purple to yellowish, borne on short peduncles 2"-4" long.
Rocky or gravelly soil, New Jersey to Missouri, Florida and Alabama. April-May.
C. reticulata Torr. Ann. Lyc. N. Y. 1: 247. 1824.
A small tree, up to 450 high, the bark rough with corky warts and ridges sometimes 1' high or more, the young twigs pubescent or nearly glabrous, green, becoming brown. Leaves thick, ovate, 3' long or less, strongly reticulate-veined, acute, scabrous or nearly smooth above, pubescent beneath, entire or serrate, the stout petioles 2"-5" long; drupe globular, red, 4"-6" in diameter, on peduncles usually longer than the petioles.
Along rivers in rocky or gravelly soil, Kansas to Texas, Colorado, Nevada and southern California. Reported to extend into Lower California. May.