BurnedOutGeek;n29105 said:I think I found it: "hardy orange"
http://www.louistheplantgeek.com/a-gardening-journal/547-poncirus-trifoliata-sp-322503520
I know it as citrus trifoliata, or trifoliate orange. The fruit is considered poisonous, or toxic. The fruit flesh is orange- like but not tasty. It's not native to the US, probably from Asia/China. A cultured plant that escaped cultivation and has adapted to our environment. I have seen a thicket of it, I would rather be dragged through the briar patch than across one of those orange plants.