The Anacardiaceae, commonly known as the cashew family or sumac family, are a family of flowering plants, including about 83 genera with about 860 known species. Members of the Anacardiaceae bear fruits that are drupes and in some cases produce urushiol, an irritant. The Anacardiaceae include numerous genera, several of which are economically important, notably cashew (in the type genus Anacardium), mango, poison ivy, sumac, smoke tree, marula, yellow mombin, and cuachalalate. The genus Pistacia (which includes the pistachio and mastic tree) is now included, but was previously placed in its own family, the Pistaciaceae.
Growing as either trees or shrubs, each has inconspicuous flowers and highly poisonous, sometimes foul-smelling resinous or milky sap. Resin canals located in the inner fibrous bark of plants' fibrovascular system found in the stems, roots, and leaves are characteristic of all members of this family; resin canals located in the pith are characteristic of many of the cashew family species and several species have them located in the primary cortex or the regular bark. Tannin sacs are also widespread among the family.
Leaves are deciduous or evergreen, usually alternate (rarely opposite), estipulate (without stipule) and imparipinnate (rarely paripinnate or bipinnate), usually with opposite leaflats (rarely alternate), while others are trifoliolate or simple or unifoliolate (very rarely simple leaves are palmate). Leaf architecture is very diverse. Primary venation is pinnate (rarely palmate). Secondary venation is eucamptodromous, brochidodromous, craspedodromous or cladodromous (rarely reticulodromous) Cladodromous venation, if present is considered diagnostic for Anacardiaceae.
Flowers grow at the end of a branch or stem or at an angle from where the leaf joins the stem and have bracts. Often with this family, bisexual and male flowers occur on some plants, and bisexual and female flowers are on others, or flowers have both stamens and pistils (perfect). A calyx with three to seven cleft sepals and the same number of petals, occasionally no petals, overlap each other in the bud. Stamens are twice as many or equal to the number of petals, inserted at the base of the fleshy ring or cup-shaped disk, and inserted below the pistil(s). Stamen stalks are separate, and anthers are able to move. Flowers have the ovary free, but the petals and stamen are borne on the calyx. In the stamenate flowers, ovaries are single-celled. In the pistillate flowers, ovaries are single or sometimes quadri- or quinticelled. One to three styles and one ovule occur in each cavity.
Fruits rarely open at maturity and are most often drupes.