[3] The species is dioecious and occurs in the moistest areas in the hottest, driest deserts within its range; it is considered poor in germination.

The fruit is tan, green, red or brown in color, turning black with age, and may persist on the tree for several years.

[2] [10] Castela emoryi is one of the few plants in its habitat that blooms in the mid-summer heat, and serves as an important source of resources for insects during that time.

[11] The Yavapai people traditionally used this as a medicinal plant, making a dermatological aid from its bud's sap.

It contains quassinoids such as glaucarubolone glucoside which has antifeedant properties against termites such as Reticulitermes flavipes,[13] or potential fungicidal activity for the control of grape downy mildew.