From what I have heard, vietnamense comes from a completely different
area than delanatii....and grows under different conditions...cooler, I
believe...I know nothing about whether it needs a lot of light, or
whether it needs an acidic mix like delanatii or a calcareous mix like
other parvi's...also, apparently most vietnamense are not that
great...only the best get photographed, and only in their first few days
after opening......Take care, Eric Muehlbauer in rainy cool Queens
NY.....with concolor and niveum in bloom