Tabernaemontana donnell-smithii is an evergreen tree in the dogbane family Apocynaceae. In Spanish, it is huevos de caballo, cojones de burro, cojón de mico, or cojotón. The name, huevos de caballo, comes from the oval shape of the tree's hanging fruit. It is native to Mexico and Central America. The type locality is San Felipe, Retalhuleu in Guatemala. Tabernaemontana donnell-smithii is similar to Tabernaemontana glabra, except that its leaves and flowers are smaller and its fruit is larger.