Desmanthus illinoensis 

Desmanthus illinoensis is a perennial weed legume growing from .3 to 1 meter tall. It has fern-like leafed branches and produces N,N-DMT in its root bark. Other names for Desmanthus illinoensis are Bundle Flower, Illinois Bundle Weed, and Prairie Bundleflower.

If this plant is smoked, it is said to have a psychedelic effect on your body. It starts to work in about 20 seconds after smoking and lasts around 10 minutes.

One of the experiences someone had was after smoking Desmanthus illinoensis:

"As I bowed (sitting crosslegged on the floor), I felt my spine open, and when I sat up, looked at my friend and felt that I was truly able to see him as God. To do this I had, while bowed down, to see the deepest cruelties that humans are capable of (rape and murder). A kind, deep voice said this was a part of the human condition that a deeply realized being is willing to see. Being willing to view this with detachment let me appreciate the depth of love I had for all people, and I was able to express this to my friend. This intensity lasted for perhaps ten minutes, and the comedown was very gradual. I am writing this almost 20 hours later; no residual effects at all, but I have felt a pleasant centeredness and afterglow."
---from Freyje

Desmanthus illinoensis by Nicholas Roberts March 31, 2008