Oregon Grape, Hollyleaved barberry, Oregon Holly Grape, Oregon Holly

Mahonia aquifolium

Physical Characteristics

Mahonia aquifolium is an evergreen Shrub growing to 2 m (6ft) by 1.5 m (5ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 5. It is in leaf all year, in flower from January to May, and the seeds ripen from August to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. The plant is self-fertile. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers dry or moist soil.

Distribution

Western N. America. Naturalized in Britain.

Habitats

Woodland Garden Sunny Edge; Dappled Shade; Shady Edge; not Deep Shade; Ground Cover; Hedge;

Edible Uses

Edible Parts: Flowers Fruit Edible Uses: Drink Fruit - raw or cooked[2, 3, 5, 95]. The fruit is almost as large as a blackcurrant and is produced in large bunches so it is easy to harvest[K]. It has an acid flavour, but it is rather nice raw and is especially good when added to a porridge or muesli[K]. Unfortunately, there is relatively little flesh and a lot of seeds, though some plants have larger and juicier fruits[K]. The cooked fruit tastes somewhat like blackcurrants[K]. The fruit can also be dried and stored for later use[257]. Flowers - raw. They can also be used to make a lemonade-like drink[183].

Medicinal Uses

Alterative Antibacterial Antipsoriatic Antiseborrheic Antitumor Blood tonic Cholagogue Diuretic Dysentery Laxative Ophthalmic Tonic Oregon grape was often used by several native North American Indian tribes to treat loss of appetite and debility[254]. Its current herbal use is mainly in the treatment of gastritis and general digestive weakness, to stimulate the kidney and gallbladder function and to reduce catarrhal problems[254, 257]. The root and root bark is alterative, blood tonic, cholagogue, diuretic, laxative and tonic[4, 21, 165, 257]. It improves the digestion and absorption and is taken internally in the treatment of psoriasis, syphilis, haemorrhages, stomach complaints and impure blood conditions[4, 238]. Externally, it has been used as a gargle for sore throats and as a wash for blurry or bloodshot eyes[257]. The roots are harvested in late autumn or early spring and dried for later use[238]. The fruit is an excellent gentle and safe laxative[257]. Berberine, universally present in rhizomes of Mahonia species, has marked antibacterial effects[218] and is used as a bitter tonic[213]. Since it is not appreciably absorbed by the body, it is used orally in the treatment of various enteric infections, especially bacterial dysentery[218]. It should not be used with Glycyrrhiza species (Liquorice) because this nullifies the effects of the berberine[218]. Berberine has also shown antitumour activity[218]. The root and root bark are best harvested in the autumn[213].

Known Hazards

Barberry, goldenseal, oregon grape and other plants containing Berberine should be avoided during pregnancy and breastfeeding. Avoid if over active thyroid gland. High doses cause vomiting, lowered blood pressure, reduced heart rate, lethargy, nose bleed, skin & eye irritation and kidney infection. Liquorice as Glycyrrhiza species nullify berberine effects [301].