I have had this tree for quit a long time (10+ years) and I was told, when I purchased it, it was a Madagascar Palm. Upon doing a google search of that name I find nothing on Madagascar Palms. Attached is a picture of the trunk close to the top. You can see that the thorns grow in groups of three, the trunk is always green, it does not branch but only leaves out. I live in Michigan so during the winter I bring it inside. The tree will lose all of it's leaves which will grow out of the top only. As you can see in the attached picture, the new growth is the lighter green. It's total length is apprx 38" in height, I bought it when it was about 6-8" tall, so what is that about 3" of growth per year. Anyway, I would love to know what kind of tree this is. Can anyone help? Lance Grand Rapids, MI