All wood types from the mod Epic Trees, as well as handful of others, return missing textures both in JEI and when placed in world. I play a sort of insane custom modpack, but I have replicated and confirmed this issue continues to occur with nothing installed but the mods required to replicate the issue. The issue also seems to be affecting wood types from Blue Skies, OrePortal, Enlightened End, Malum, Nether's Exoticism, and Tinker's Construct (and maybe a few others, there's a lot to poke through!).

Screenshot is from the test setup I created with just this mod, Epic Trees and others necessary for testing (such as dependencies) but no performance mods, sodium, optifine, shaders, etc etc. I have not isolated every mod mentioned in the same way but I would assume they are all stemming from the same or similar issues.

FWIW, another mod that does dynamic asset generation for modded woodtypes, Every Compat (Wood Good), also seems to have some issues with the wood types from Epic Trees and OrePortal, so it is very possible that the those devs have done something strange with the way they are handling wood textures, but I am not experienced enough with modding to theorize what that could be. If this is an issue with how they're handling things, please let me know, and I'll go report an issue over there instead!