I know that the fancy way to pronounce "pecan" is something like [pih-KAHN], but where I come from — and we grow them — it's a [PEE-kan]. I can hear you snickering. But I will not be deterred — I'll continue to say it the right way.
The pecan tree is a large hickory (same word in French) — Carya illinoinensis or illinoensis — that has roughish bark and brittle wood. It is widely grown in the warmer parts of North America for its edible nut, which has a thin shell and a rich, buttery taste. It's the American walnut that's better-tasting than the nut called la noix de Grenoble in Quebec or the English walnut in the U.S.
Wikipedia says that the pecan tree can live and produce edible nuts for as long as 300 years. Thomas Jeffereson and George Washington planted pecan trees on their estates in Virginia. The nut has been grown commercially only since the 1880s. I think the trees and nuts have been "improved" by breeding and selection.
Pecan comes from an Algonquian word meaning "a nut requiring a stone to crack" — but the ones that grow on the tree pictured above, which grows in the back yard of the house in Morehead City that I grew up in, are called "paper-shells" and are very easy to crack open.
I'll be packing a bag full of pecans to take back to Saint-Aignan on Tuesday. We'll enjoy them in pumpkin bread, applesauce cake, or pecan pie. You can freeze the nutmeats with good results after you take them out of the shells, by the way. I'd love to grow pecans in Saint-Aignan, but I'm told the summers are not hot enough to allow the pecans to ripen.