PLANT: Dioecious shrubs or small trees, most with at least some spinose branchlets; stems green. LEAVES: alternate, simple, mostly less than 5 cm long, sometimes scalelike and caducous (as in ours), or mostly persistent. INFLORESCENCE: a much-branched axillary panicle of cymules or reduced to various degrees, even to a single flower. FLOWERS: imperfect, 4-8-merous; petals several times larger than sepals; stamens mostly 2-3 times as many as petals, inserted around a glandular disk; pistils mostly as many as sepals, each with one ovule, separate below, united by the styles, the stigmas separate. FRUIT: a star-shaped cluster of carpels joined centrally, each carpel at maturity nearly dry, laterally compressed, drupe-like, deciduous or persisting for several years. NOTES: Ca. 15 spp. sw & sc U.S. to S. Amer. (For R. R. L. Castel). REFERENCES: Brasher, Jeffrey W. 1999. Simaroubaceae. Ariz. - Nev. Acad. Sci. 32(1).