Forget the "trees". I've heard this works better...
The Definitive Instructions for Smoking Banana Peels
Go to the grocery store and buy 10 pounds of bananas. (You used to need 200 pounds, but the potency has gone up 20x in the last 30 years.)
Remove the skins from the fruit. Save the fruit for later - if you mix it with orange juice and drink it while you're smoking, it'll make you trip real hard.
Dry the skins in the microwave. This won't affect the potency, as bannadine is not microwave soluble.
The next two steps are a simple nonpolar-polar extraction of the bannadine. This is necessary to get rid of the fungicide they put on the skins, which is a type of strychnine. Grind up the dried peels really well, and soak them in methylene chloride (zippo lighter fluid makes a good substitute). Let soak for 2 days, and then rinse well with ether. Discard the liquid and save the mush.
Take the mush from step 4 and soak it in ethyl alcohol for another 2 days. Filter, and put the mush aside - you won't be smoking it.
Evaporate the alcohol. The resultant crystals are 150% pure bannadine. Put these in your pipe, light up and enjoy! (Keep reading for the secret step 7!)
Bannadine is normally only active when smoked; that's why eating bananas won't do anything. However, that mush left over from step 5 is pretty tasty, and that's how I discovered that bannadine is orally active if potentiated by dried peanut skins! Yes, its true. I looked up the structure, and it turns out bannadine is really closely related to DMT - it has carbon atoms and everything!
EDIT : No, I didn't write this. No, I've never tried it. Yes, this was extremely sarcastic. No, I won't pay your hospital bills if you're stupid enough to try this. No, you can't blame me when your mom finds out.