Ploidy refers to how many sets of chromosomes a cell nucleus contains.
Usually, every cell has two copies of a chromosome, and is designated
2N. Usually, higher ploidy number means more robust plant (sequoiae are
6N and are huge trees, and some of the most robust)- if some genes get
damaged, they have more backup genes to work with. However, a 3N plant
can only produce progeny with a 3N plant, and 4N plants, preferably with
other 4N plants.

Cheers,
Xi

wrote:
I've most recently seen it (4N) on a phragmipedium given to me. Thank you.