If it's the regular red Nanking; it should grow true as it's a Chinese native and not a hybrid. As for the 'Black', that's a pretty vague description. Most cherries as cultivars or hybrids, so not likley to grow same as the parent.

Thanks for the reply. I have the Nanking Cherry but have backed off on the Black Cherry for now.

Peggy

There's a Black Cherry tree that's native, at least to the midwest. It produces small black fruit that's mostly seed that some people used to make jelly. If that's the cherry you're talking about, it will breed true, but jelly is the only thing the cherries are good for.

Peggy,
I hate to burst your bubble, but I've got some serious doubts about whether Nankings will get enough chill hours to fruit for you in zone 7; they may, but I hope you're not anticipating big, tasty cherries - what you'll get are tiny little things, not quite as large as a C.florida(flowering dogwood) berry - and mostly pit, at that.
Take a look at the seeds you got - imagine about 1/8" of pulp surrounding them. That's all you get.

Nanking is really more of a plant for folks in really cold areas, who can't reliably grow the larger cherries, due to their severe winters, or for folks who plant 'em as a food source for birds.

Am aware the Nanking is a very small fruit. Was just curious if it would produce at all in our area. I'm interested in the blossoms and if it produces fruit, that is a bonus.

Peggy