Many species in this category are like d, e or g below - one ovary with two or more locules. In a small percentage of species there are multiple (usually between 3 and 5) free ovaries per flower, but the ovaries are united by a single style (see ‘f’ in the image or see the gynobasic images). Because we are considering the whole of the gynoecium if one part (i.e. stigmas, styles, or ovaries) is fused, even if the others are free from each other, then we consider the carpels fused. For example, ‘f’ would have a floral formula of G(4) even though the ovaries are free.
Illustration from Clarke, I. & Lee, H. (2003) Name that Flower, Melbourne University Press, Victoria.