Dioecious or polygamo-dioecious; infls (or solitary fls) axillary, pedunculate; staminate fls in short racemes or heads, with minute sep, 5-10 small, imbricate pet, and 8-15 stamens much longer than the pet in 2 ±definite whorls; "perfect" (but functionally pistillate) fls solitary or in infls of 2-4+ and sessile (in ours) on slender peduncles, the sep, when present, usually 5, the pet 5-8, the stamens fewer than in the staminate fls and about equaling the pet, or wanting; ovary unilocular and with a single style and ovule, seldom with a more or less well developed second locule and style; fr a drupe, crowned by the persistent disk, each locule opening apically by a triangular valve at the time of germination; deciduous trees or large shrubs with alternate lvs. 5, N. Amer. and se. Asia.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.