The Goma gara (gara meaning pattern) is representational of the sesame flower.
Sesame seeds and oil have long been a staple in Japanese cuisine. It is natural that the sesame flower would be represented in Japanese craft and art. Harvested in autumn, the sesame plant grows up to 6' tall and bears small white bell shaped flowers.
This is a relatively simple pattern that demands perfect execution. Sets of multiple parallel lines will extenuate any error of the shokunin.