Dwarf Cavendish banana leaf

Life and Mathematics.

Hyperbolic spiral, I think. It begins at an infinite distance from the pole in the centre, it winds faster and faster around as it approaches the pole.

The Dwarf Cavendish banana (or simply Cavendish banana) is a banana cultivar originally from Vietnam and China. It became the primary replacement for the Gros Michel banana in the 1950s after crops of the latter were devastated by the Panama disease.
It is one of the most commonly planted banana variety from the Cavendish group, and the main source of commercial Cavendish bananas along with Grand Nain.