Monoecious or dioecious trees, shrubs or perennial herbs, with alternate or opposite simple mostly evergreen leaves, the sap not milky. Flowers clustered or solitary, regular, bracted, with or without a perianth (calyx). Petals none. Staminate flowers with 4-7 distinct stamens, the anthers 2-celled; sometimes with a rudimentary pistil. Pistillate flowers with a 2-4-celled (mostly 3-celled) ovary, with 2 or 1 anatropous ovules in each cavity; styles as many as the ovary-cavities, simple. Fruit a capsule or drupe, its carpels 1-2-seeded. Embryo straight; endosperm fleshy, or almost wanting.

About 6 genera and 35 species, only the following and the Californian Simmondsia in continental North America.