O.K, O.K. already. Problem solved. There's the she-oak. Or ironwood. That's it. Casuarina family. It has a zilliion names around the Pacific nations. The swamp she-oak is just one variety (swamp oak to some, such as the informant who looked at my wild back yard and said something like "I see you've lots of swamp oaks"). No. She-oaks, and the ones I've seen mentioned most, in a quick googling and Wikipedia-ing, are River She-oak and Beach She-oak.
I did its wood an injustice. It does burn well (hot, little ash residue) but it needs a good fire going to feed it to as fuel. In other words, not so flash as kindling, and the first lot I put on my log fire was particularly fresh-cut and damp, and all I had at the time. Swamp she-oak, all is forgiven. I have decided against wearing a placard saying 'Ask me about swamp oaks'.