Opening of floral buds into flowers, is a type of

Plant movements are autonomic (spontaneous, caused by internal factors) or paratonic (induced by external stimuli).
Movements are further of two kinds: growth movements, caused by unequal growth, and variation movements, caused by reversible changes in turgor.
The opening of a floral bud is caused by more growth on the upper (inner) surface of the sepals and petals than on the lower (outer) surface. This is called epinasty.
Epinasty is an irreversible growth movement, and it is controlled internally (by auxin distribution), so it is autonomic.
It is not a movement of locomotion, because the plant or organ does not move from one place to another.
It is not a movement of variation, because it is not due to turgor changes.
So the opening of floral buds into flowers is an autonomic movement of growth.