Examples from the Web for bitternut
They are bitternut (Hicoria minima), pignut (Hicoria glabra), and mocker nut (Hicoria alba).American Forest Trees|Henry H. Gibson
On bitternut they grow fast, but at the end of eight or ten years are inclined to slow up.
At any rate, the poorest growing pecan in the University of Illinois orchard is on a Wisconsin bitternut understock.Northern Nut Growers Association Report of the Proceedings at the Forty-Second Annual Meeting|Northern Nut Growers Association
The figure is surpassed by one bitternut hybrid the Beaver 29kg, and by the Hatch bitternut 19kg, and the Halesite bitternut 13kg.
There is also a variety of bitternut from Iowa known as Cedar Rapids, but the two are quite unlike and should not be confused.Northern Nut Growers Association Report of the Proceedings at the Twenty-Fifth Annual Meeting|Northern Nut Growers Association