Polished hickory string, Northeast hickory and ordinary walnut are from the walnut family, but is a different species of two plants. First of all, there is a clear difference in size, ordinary walnut larger, while the Northeast hickory head small; Secondly, in the origin and distribution, the Northeast hickory is produced in the Northeast region; and ordinary walnut is initially from the West (that is, today's Central Asia) introduced to the production area is more widely distributed; In addition, the two in the therapeutic effects of the focus is also different, the Northeast hickory heavy in the nourishment of the kidney yin, set the gasp, while the ordinary walnuts are long in the The two are also different in their therapeutic effects.