The choice of the species name “opaca” by William Aiton (1731- 93) is of interest to me.
The Latin root “opacus” is said to mean opaque, shaded, dark or dull. Opaque is further defined as “not relecting light.”
Some authorities describe the top of the leaves as “dull” or “leathery” supporting the choice of “opaca.”
Other descriptions use the term “glossy.” I think that is a better description of the leaves of a healthy tree in North Carolina. In that case, “opaque” does not seem appropriate for the top side of the leaves, but perhaps the underside?