Prickly ash is common throughout central Illinois and the whole eastern U.S.A. in the form of one species or another. We ran into a patch of the local one, Z. americanum in Sand Ridge State Forest in mid-August, and the fruits were ripe. We had recently read in the back of a book by Martin Yan, a.k.a. Yan Can Cook, that Szechwan peppercorns were none other than the berries of prickly ash. Neither of us had ever had Szechwan pepper by itself, so we didn't know what to expect. We chewed on some of the "berries" - actually a sort of red fleshy capsule enclosing a hard black shiny seed, and got a funny surprise.
The flavor was sharp and sort of lemony, but the really interesting part was the powerful, cool, numb tingling that filled our mouths. We also both started coughing as a result. After a few minutes the tingling and numbness subsided, and left us wondering whether Mr. Yan was talking about this plant, a substantially different species of Zanthoxylum, or some other plant that was mistranslated as prickly ash.
It turns out, after some research, that Mr. Yan was right. Though true Szechwan pepper comes from several Asian species, particularly Z. piperitum, Z. simulans, and Z. sancho, the American sort might do just as well, as the description of the spice's properties agree with what we experienced. Wikipedia states: "Sichuan pepper has a unique aroma and flavour that is not hot or pungent like black or red peppers, and has slight lemony overtones, but with a kind of tingly numbness (caused by its 3% of hydroxy-alpha-sanshool) that sets the stage for these hot spices."
And it's also supposed to be toasted before use.
We collected a few fruits, which look like this:
I removed the seeds and stems, and toasted the capsules in a dry skillet as per Mr. Yan's instructions. They shrank, turned brownish, and are now less intensely tingly, and tastier.
We look forward to cooking some Chinese food with them.
Verdict: Good, if you don't eat too much of the raw stuff by itself without knowing what you're getting into.