Texas Persimmon (Diospyros texana) will ripen and provide a tasty treat for humans, birds, and mammals.
For those of you interested in ethnobotany you might consider the following website. Learning to be more self-sufficient begins, I believe, with a proper understanding of native plants. You will remain a neophyte woodcrafter (bushcrafter) if you refrain from knowing, in detail, the plants around you. This includes a thorough knowledge of the ethnobotanical history of the area where you live. The following website is a good place to begin.