Got a few sticks of this in a pile of ash/cherry/maple logs. Heavy and stringy. Takes the Super Split at least 3 whacks per split on straight pieces that are only 10-14" in diameter. The two comparison pics have a piece of ash on the right.
It is some variety of elm. I dig it, it shreds like fibrous pulled pork. Lots of surface area to light off.
Looking at other pics of black gum on the internet I think you are right. I have about 20 rounds left to split but I think I'm going to donate it to my buddy's boiler wood pile. Low BTUs, looks ugly in the stacks and hard to split so no thanks. Such a shame though because they are the perfect size rounds.
My only experience with it was with one log i took from a scrounge not knowing what it was at the time. FHC IDed it and i split it anyhow for chits & giggles. Here's the thread It Takes a Lot of GUMption to Hand Split Tupelo!
That's gum, even hydraulics hate it.....lol If yer gonna keep it, just noodle it up into quarters, and keep the noodles for tinder bundles.