The marks of a slightly round-headed chisel are visible on the leaves. As elsewhere on the Column it is clear that the carvers responsible worked along the length of these leaves rather than across them in order to give the impression of veins on their surfaces.
Drill holes are visible around the edges of these leaves and in those areas where the details are carved in the round.
This is a good example of some of the more detailed trees on the Column. The variety of ways in which these trees are handled would seem to indicate that at least two carvers were tasked with carving these details.