Casimiroa edulis.

Botanical name: 

Casimiroa edulis La Llave. Rutaceae. Mexican Apple. White Sapota.

Mexico. This tree grows wild and is cultivated in the states of Sinaloa, Durango and elsewhere in Mexico and is known by the name of zapote blanco. The fruit is about an inch in diameter, pale yellow in color and is most palatable when near decay. It has a very rich, subacid taste, and the native Californians are very fond of it. Masters says its fruit has an agreeable taste but induces sleep and is unwholesome and that the seeds are poisonous.

Sturtevant's Edible Plants of the World, 1919, was edited by U. P. Hedrick.