The ornamentation of the orbicule surface often resembles that of the pollen sexine. Different hypotheses about their function have been proposed, including them just being a by-product of pollen wall sporopollenin synthesis.
Ornamentation on the orbicule's surface often corresponds to patterns found in the pollen sexine. Various theories about their function have been proposed, including them being a result of sporopollenin synthesis during the formation of pollen walls.