Figure 5. Illustration of judging the type of flowering crabapple pollen grain exine ornamentation (Wholly Regular Multi-pattern Type, WRM type as an example).

, (1/8 ≤ a_i ≤ 1, 0 ≤ n ≤ 8, 0 ≤ A ≤ 1). A represents the area of 1 unit with regularly arranged striae (relative area to the surface area of pollen equatorial plane, which was defined as 1; the size of the area by visual method.); n represents the number of units with regularly arranged striae where a ≥ 1/8; A represents the total area of all units with regularly arranged striae where a ≥ 1/8.