View photos of the edible plant Celtis pallida (Desert hackberry), profiled in the Wild Edible Series: Sonoran and Texas: Vol 1.

A passage from Sonoran Desert Food Plants:

It is common to lower elevation areas, particularly
along draws, gullies, rocky hillsides, and on sandy flats. It is native to both Sonoran and Chihuahuan Deserts.

A passage from Wild Edible Plants of Texas (Volume 1):

Celtis pallida has a fleshy mesocarp and large crunchy seed – the entire berry can be eaten raw, prepared as a jam/preserve, or dried and ground into a meal.