4 oz oregon grape/mahonia (berberis) aquifolium extract we prepare our oregon grape extract from the young lateral roots of mahonia (berberis) aquifolium shrubs which are custom wildcrafted in their wild mountain habitat in the pacific northwest. To assure optimal extraction of oregon grape'spounds, the roots are hand-dug only in late autumn or early spring, and arethen carefully shade-dried and thoroughly extracted. Our oregon grape is never fumigated or irradiated. Dry herb / menstruum ratio: 1: 5.