Dunstan was originally a cross between American and Chinese. As chickenlittle points out, it is also a trade name of Chestnut hill. Most of the trees they sell now are grown from seed from the originally grafted Dunstan trees. They have done a tremendous job marketing to the hunting community. Dunstan chestnuts have some great characteristics, but they are over-hyped in the hunting community and thus you pay a premium for them. There are lots of other Chinese chestnuts to consider. The wildlife group sells some patented AU Buck III and IV. They are fully Chinese but also have some interesting characteristics. The AU Buck III are supposed drop from late September through mid October and the IVs are supposed to drop from October well into November. Most other chestnuts drop in September.
I do like some of the characteristics that Dunstan chestnuts offer but didn't want to pay the premium, so I started growing my own from nuts. That has worked out pretty well so far. I wouldn't do it for just a few, but for high volumes, the setup cost amortizes pretty quickly.
In most cases, you will still get a lot of wildlife value out of any old Chinese chestnut that is not a named variety.
Thanks,
Jack