The spot patterns on those green background petals are what makes it in balance with the bright purple shading on the front petal ( bet there's a technical term for that front petal). I like this one better than the plain green background petals that I saw in some of those pictures.
Zygopetalum is now on my 'want list'. I need to do some reading to find out if the humidity requirements are high. Not sure if I could grow it here where the summers are dry. Sure is a pretty one though.
