From limited reading, it appears that USDA sent some propagated jujube selections to Texas and Oklahoma in 1920s. Those trees are general purpose trees, not particularly good for fresh eating. Maybe good for drying.

Then in 1950, USDA developed the "Chico" or GI 7-62 and released to public. Chico is good for fresh eating, but the distribution is limited.

Only from 1990s, the new and good fresh eating jujube varieties were imported more to US.

So for the mature jujube trees in Texas, mostly likely they are the "Chico" type, developed by USDA.

I remember a huge jujube tree in Dallas area. The fruits are medium to large, shaped like Sugar Cane, but larger. It fits the description of Chico or GA866.

As for their seedling, since jujube seeds do not come true, I figure the seedlings would be close to wild jujube (in China). The quality of the fruits may not be very good. Or it is unknown.

In 1920s, USDA released several varieties. Only one is good for fresh eating. So I believe both Li and Lang were released at that time. This is why Li and Lang are probably the only known jujube to the public, and the only widely distributed.

After 1990s, there are so many new varieties. There are many many more in China, some never named.

The size is about 30' wide? It covers almost the backyard.

And the owner says "it was sending runners under the drive and alley, to back neighbor's yard."

So I guess the old tree may not be grafted. Or the rootstock may be a good one and can set large fruits....

"Chance discovery" means it comes from seedlings. The seedlings do not come true. So they can be better or worse. Same story with Granny Smith apple.

Some say Chinese grow 700 varieties of jujube. But can people count the varieties? Some grow in the wild and never discovered. They are small trees, grow in all kinds of soil and do not need so much water to survive....