I suppose that having learned that there was not just "ground chillies" but Deggi Mirch, Kashmiri Mirch, and probably a few hundred other varieties as well, it should not have come as a shock to learn that there was more than one type of turmeric -- but there is ! A very interesting post by Ajoy Joshi (http://thoughtsfromajoy.wordpress.com/2012/08/08/the-name-of-the-game-is-consistency/), which focusses on a technique for retaining the bright green colour of spinach for up to a week after cooking.
** Phil.