My teeth's got dry finish, cuz I eats my spinach

So I’m plowing through a big ol’ bowl of raw spinach today (because I think it’s yummy, and if you don’t, that’s your own problem) and afterwards, I notice my teeth are really rough-feeling to the tip of my tongue, rougher than usual. I’ve noticed this many times before, but not when I was so close to a keyboard with a SDMB window already open.

So anyone out there in Doperland know what causes this? It almost feels as if the teeth have been dried out on the surface, but that’s silly, given that they spend all their time in a fairly wet environment.

The consensus seems to be that it’s the oxalic acid in spinach that makes your teeth feel wierd. A couple centuries ago oxalic acid was used as a teeth whitener. Nowadays its better known as the the stuff that makes rhubarb leaves (not very) poisonous.
http://www.flynn-produce.com/aboutmar2000.htm

http://essiac-info.org/herbs2.html

http://www.sydneymarkets.com.au/fandv/rhubarb.htm

Well, there ya go. A hole in one. Thanks Squink.