In a small bowl, combine the egg whites and water; beat lightly with a fork. Dip a paint brush in the egg whites and gently paint a flower covering the petals thoroughly but not excessively. While still wet, gently sprinkle the coated petals with the superfine sugar. Put the crystallized flowers on a sheet pan lined with waxed paper to dry for 12 to 24 hours. Use to top cakes and desserts.