Tree to 20 m, the trunk soon deliquescent; lfls 3-5 or on rapidly growing shoots to 9, pinnate, lanceolate to ovate or oblong, coarsely and irregularly serrate or with a few shallow lobes; dioecious; fls apetalous, appearing with or before the lvs, the staminate in sessile, umbel-like fascicles, drooping on slender pedicels, the pistillate in drooping racemes; disk wanting; mericarps 3-4.5 cm; 2n=26. Moist, especially alluvial soil; N.H. to Fla., w. to the Pacific, and irregularly in Mex. and Guat. Var. negundo, the common e. Amer. var., has glabrous, often glaucous twigs. (Negundo n.; N. nuttallii) Var. interius (Britton) Sarg. (Negundo i.), with velutinous twigs and usually with tufts of hairs in the vein-axils beneath, is chiefly western, occasionally extending to Minn. and Mo. Var. texanum Pax, with similarly hairy twigs, rather densely puberulent frs, and short-acuminate lfls pubescent over the whole lower surface, occurs chiefly from the Ozarks to Tex., extending e. to s. Ind.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.