Plants to ca. 25(-35) m, with sour-tasting sap. Stems terete. Leaf blades turning red in autumn, 5.5-23.5 × 2-8 cm, base cuneate to rounded, apex acute to acuminate. Flowers: calyx lobes 1-2 × 0.7-1.4 mm; corolla 4-7 × 2.5-5.5 mm; filaments 2-3.5 mm; anthers with locules narrowed distally, tubulelike; style strongly impressed into apex of ovary. Capsules 3.5-8.5 × 2-4 mm, unicellular-hairy; placentae basal. 2n = 24. Flowering late spring-summer. Usually well-drained, acid, broadleaved forests on slopes, bluffs, in ravines, or along streams, ecotone areas in pinelands, swamp margins; 0-1700 m; Ala., Fla., Ga., Ind., Ky., La., Md., Miss., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Va., W.Va. Oxydendrum arboreum is often used as an ornamental; it sometimes persists after cultivation (or rarely escapes from cultivation) in regions north of its native range; specimen-based records from New Jersey and southern New York appear to represent such escapes from cultivation.
From Flora of Indiana (1940) by Charles C. Deam
There are a few trees of this species in two localities about five miles apart about seven miles northeast of Cannelton in Perry County. The largest trees were located on the Walter Hafele farm in Township 6, Range 2 W, section 21. They were associated with beech near the base of a sandstone slope and measured 41 inches in circumference at breast height, had a clear bole of about 25 feet, and were about 55 feet high. There is a specimen in the herbarium of Wabash College collected in the vicinity of New Albany, Floyd County, June 14, 1836, by Dr. A. Clapp. The report by Dudley for Monroe County may be safely ignored.
Tree to 20 m, beginning to fl at 2-3 m; lvs oblong, elliptic, or lance-ovate, 10-15 cm, acuminate, entire or serrulate; petioles 1-1.5 cm; racemes 4-7 at end of each branch, widely spreading, 5-15 cm, persistent; pedicels 3-8 mm, minutely bracteolate near the middle; cor 6-7 mm; fr 5-7 mm; 2n=24. Woods, Pa. to s. Ind., s. to Fla. and La. June, July.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.