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.
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.