Flowers and Grasses of the Four Seasons Attributed to Sotatsu school Japan; Edo period (1615-1867), about 1620 - 1650 The screens illustrate the changes from spring to winter with representations of the flowers, grasses, plants, and vegetables that bloom in each of the seasons. The vegetation is painted in the "boneless" or outlineless technique. In this method, shapes are created using color rather than filling in outlined forms.