Dioecious; staminate fls in cylindric catkins, with deeply 4-lobed cal and 4 stamens; pistillate fls in dense, globose heads, with 4-lobed cal and one long, exserted style; fr globose, dense, consisting chiefly of the accrescent calyces, from which the orange achenes protrude; trees or shrubs with serrate or lobed, alternate lvs. 7, e. Asia, Polynesia.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.