Ploidy is the the number of complete sets of chromosomes in normal non-reproductive cells.
From The Old Problem of Species in Rosa: "The characteristic number of chromosomes in each cell of a species [rose] is a multiple of 7, called "n", [which] varies from 2 x n (14) in diploids to 8 x n (56) in octoploid species."
2 sets =14 > diploid
3 sets =21 > tripoloid
4 sets =28 > tetraploid
5 sets =35 > pentaploid
6 sets =42 > hexaploid
8 sets =56 > octoploid
10 sets=70> decaploid