Other Species — While Berberis aquifolium is generally designated as the source of Oregon grape root, other species of Berberis are met with in the market under the name grape root, and their use is sanctioned by the United States Pharmacopoeia.
The species most commonly collected with Berberis aquifolium is B. nervosa Pursh, which is also found in woods from California northward to Oregon and Washington. This is 9 to 17 inches in height, with a conspicuously jointed stem and 11 to 17 bright-green leaflets.
Another species of Berberis, B. pinnata Lag., attains a height of from a few inches to 5 feet, with from 5 to 9, but sometimes more, leaflets, which are shining above and paler beneath. This resembles aquifolium very closely and is often mistaken for it, but it is said that it has not been used by the medical profession, unless in local practice. The root also is about the same size as that of aquifolium, while the root of nervosa is smaller.
Some works speak of Berberis repens Lindl. as another species often collected with aquifolium, but in the latest botanical manuals no such species is recognized, B. repens being given simply as a synonym for B. aquifolium.
Description of Rootstock — The rootstock and roots of Oregon grape are more or less knotty, in irregular pieces of varying lengths, and about an inch or less in diameter, with brownish bark and hard and tough yellow wood, showing a small pith and narrow rays. Oregon grape root has a very bitter taste and very slight odor.
Collection, Prices and Uses — Oregon grape root is collected in autumn and brings from 10 to 12 cents a pound. The bark should not be removed from the rootstocks, as the Pharmacopoeia directs that such roots be rejected.
This root has long been used in domestic practice thruout the West as a tonic and blood purifier and is now official in the United States Pharmacopoeia.
The berries are used in making preserves and cooling drinks.