Evidently we’ve been mis-identifying our persimmons.
The prolific persimmon tree has acorn-shaped fruit like the red one here. Those are apparently Hachiya persimmons.
The younger tree with only a few fruit not yet ripe has flat-bottom persimmons like this yellow one. Those appear to be Fuyu persimmons.
See, for example, this GrubMarket blog post, Fuyu vs. Hachiya: How to Use California Persimmons.
They’re both varieties of the Oriental persimmon, Diospyros kaki.
-jsq
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