Hello, I had directed this query originally to "Dr. Phipps", but she didn't know what it was, and recommend I send this query to you. There is a plant in my back yard that I have no idea what it is. To describe the plant, it's about 6' tall, bushy, woody trunk, a cluster of trunks at the base, about an inch thick. Where the leaves come out a thick sharp thorn grows. The leaves burst out in little bunches, a stem with a compound leaf of 5 jagged leaves, all forming at the same point. It has a tiny cluster of flower buds, I think, but isn't blooming yet. It's definitely not a conifer. I've attached three images, I hope you can solve this mystery!