Surely math is the essential tool to describe such things?

Iris Cohen schreef
You lost me. Here we have a situation where, due to a genetic quirk or
incompatibility, the leaf has a twist. It looks as though the dorsal surface
of the leaf does not quite fit the ventral surface properly. There is
something about the growth process of the leaf which perhaps causes one
surface to grow at a different rate from the other. Maybe my left brain is
asleep, but I don't see where math comes in.

Iris,

+ + +
Aren't you doing it yourself?
"one surface to grow at a different rate from the other"
ie two rates, in a curious relationship to each other. Rate of growth is
best expressed in a mathematical formula. Two rates of growth are ...
PvR