[answered] mystery plant

I found this plant by the dumpster, where people abandon their plants. I thought it was dead, since the only thing visible was a horizontal brown stick with some brown leaves attached to it. I put it in the garage before I left town for a month. When I came back, I was all ready to transplant something else into the pot, when I noticed that there was a spike coming out of the dirt that appeared to be alive. A few weeks later, I have this plant, but I don't know what it is!

Done