The plant will appear to be taller because the fish is observing an object placed in a rarer medium.
Light from the object is incident on the interface of the two mediums it bends towards the normal. If this ray is extended backwards it appears to come from a point that is at a greater height than that at which the object is placed.
The apparent height of the object will be 1.33 x1.0m = 1.33m, as the refractive index of water is 1.33.
You have rated this answer /10