Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Genus Description - Lvs simple and usually palmately veined and lobed, or less often pinnately or palmately compound with few lfls; fr normally a double samara with winged mericarps, the seed-bearing base of the mericarp thickened and not winged. (Argentacer, Negundo, Rufacer, Saccharodendron) 110, cosmop.