Nancy:
That's very helpful. Thank you. For some reason, my brain wants yin to be contracting and yang to be expanding. It may be an issue of the way they sound and perhaps the fact that yang is a longer word. Thinking of it as acidic and alkaline is much easier for my wee brain right now.
I was not aware that other nightshades (except tomato and tomatillo) were acidic. Potatoes seem rather benign in that respect; so I am among those a bit shocked by them being acidic. Perhaps a few years of being strict will allow me to on occasion enjoy my beloved salsa. :p
Anne