Fraxinus quadrangulata Michx.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Tree to 30 m, with sharply 4-angled or narrowly 4- winged twigs; lfls 7–11, commonly lanceolate, usually long-acuminate, broadly cuneate to subrotund and usually inequilateral at the petiolulate base; fls perfect; anthers blunt or cleft at the tip; fr flat, elliptic to narrowly oblong-obovate, 2.5–4 cm × 6–10(–12) mm, usually emarginate, the wing extending nearly or quite to the base; cal minute, soon deciduous. Moist woods; s. Ont. to s. Mich., s. Wis., and e. Kans., s. to W.Va., Ga., Ala., and Okla.