, the only species in the whole simmondsiaceae family, is a densely-branched, evergreen shrub of desert regions, most widespread in central Arizona and southern California. Leaves are dull in color, leathery of texture, relatively thick and essentially hairless, blunt-pointed at the tip. Branches are woody, with smooth bark.
Plants are dioecious, bearing male or female flowers on stalks of up to 0.7 inches. Male flowers are pale green, with from eight to 12 stamens (usually ten), female flowers more yellowish, with one pistil, three styles and three stigmas; both flowers have five unfused sepals, and no petals. Male flowers are clustered, and pendent, female flowers usually solitary. Anthers are yellow, the filaments whitish. Flowers, or flower clusters, are attached by hairy stalks, up to 0.8 inches in length.