Pictured below are (top) Two-Row Stonecrop and (below) its sport, Tricolor Stonecrop (Sedum spurium 'Tricolor'.
Tricolor Stonecrop has oblong, variegated leaves with a bit of rose intermingling with the white edging. Any seeds produced by the flowers on Tricolor Stonecrop probably will produce Two-Row Stonecrop plants (solid green, round leaves).
If you acquire a plant of Tricolor Stonecrop, you should put it where you can keep an eye on it as it will keep trying to revert to Two-Row Stonecrop.
When you see sprouts on Tricolor Stonecrop that have solid green, round leaves, you should remove them to prevent them overtaking the variegated form of Tricolor Stonescrop. You don't have to discard the sprouts, however. You can plant them in moist soil where they will root and eventually produce lovely, mature plants of Two-Row Stonecrop.