Uncommon fruits

Uncommon Fruits Worthy of Attention: A Gardener's Guide (1991) by Lee Reich

The author provides an interesting list of choices.

Pawpaw (Asimina triloba) deciduous tree hardy to zone 5
Gooseberry (Ribes uva-crispa, Ribes hirtellum) deciduous shrub hardy to zone 3
Nanking Cherry (Prunus tomentosa) deciduous bush hardy to zone 3
Medlar (Mespilus germanica) deciduous tree hardy to zone 5
Juneberry (Amelanchier spp.) deciduous shrub or tree hardy to zone 3
Maypop (Passiflora incarnata) herbaceous perennial vine hardy to zone 6
Kaki and American Persimmons (Diospyros spp.) deciduous trees hardy to zone 5
Raisin Tree (Hovenia dulcis) deciduous tree hardy to -10F
Black Currant (Ribes spp.) deciduous shrubs hardy to zone 2
Elaeagnus (spp. including Gumi, autumn olive, russian olive) dec. shrub/tree zone 3
Actinidia (spp. of various kiwifruits) woody vines hardy to zone 3
Jujube or Chinese Date (Ziziphus jujuba) deciduous tree to -20F
Alpine and Musk Strawberries (Fragaria spp.) herbaceous perennials to zone 3
Currants, Red and White (Ribes spp.) woody shrubs to zone 3
Mulberry (Morus spp.) large deciduous trees to -25F
Lowbush Blueberry (Vaccinium augustifolium) woody shrubs to zone 3
Asian Pear (Pyrus spp.) deciduous trees to -60F
Jostaberry (Ribes nidigrolaria) gooseberry/black currant hybrid to zone 4
Cornelian Cherry (Cornus mas) dogwood tree to zone 4

Appendices on pollination, planting, pruning, propagation, etc.

Unfortunately, the contact list is long out of date, with many of the suppliers now out of business.