Ray
Impatiens mirabilis is a really neat Impatiens. It is one of the few low land Impatiens meaning it likes heat and humidity.
It comes mostly form Thailand and gets a lot of rain but grows in lime stone cliffs. So give it a vary gritty soil with some lime stone chips and organic matter. Pot it up small and let it dry out some. To pollinate it just dab some pollen on your finger or brush and place it at the tip of another flower that has dropped the pollen cap. The seed pod will swell and look like a football and be careful because, when ripe, they will explode. The seed should look dark brown and not pale. Place the seed on the surface of a similar mix and they should sprout. You may want to cover the pot with plastic wrap and watch out for snails and slugs. I have lost several species because of them at the seedling stage.

There are several species in this complex currently under review, all of them tuberous species from Thailand or N. Malaysia. I am growing and blooming some of them and have lost several through rot which occurs very unexpectedly. A friend who grow this to tree size advised that they should be sprayed with different fungicides in rotational basis. My experience also shows that their roots will reach deep down and out of the pot onto the ground whereupon they do not like to be moved, pot and all, as this has caused the sudden rot of 2 of my plants. All this of course depends on your growing environment - how humid and such.
Cheers.

Ray--How did you do with this species?

--Rick in CT