Practical ecological knowledge for the temperate reader.

Oregon-grape - Mahonia Sp.

Family: Berberidaceae - Barberry Family

"Habit: Shrub, generally rhizomed. Stem: spreading to erect, branched, spiny or not, vine-like or not; inner bark, wood generally bright yellow; over-wintering bud scales deciduous or not. Leaf: simple or pinnately compound, cauline, alternate, generally leathery, generally persistent; leaflets generally 3--11, +- round to lanceolate, generally spine-toothed. Inflorescence: raceme, axillary or terminal. Flower: sepals 9 in 3 whorls of 3; petals 6 in 2 whorls of 3, bases generally glandular; stamens 6; ovules 2--9, stigma +- spheric. Fruit: berry, spheric to elliptic, generally purple-black.
Species In Genus: +- 600 species: temperate worldwide. Etymology: (Latin: ancient Arabic name for barberry) Toxicity: Roots often TOXIC: spines may inject fungal spores into skin. Note: Contact with filament causes stamen to snap inward, possibly to deposit pollen on pollinator." [Jepson]

"Some authors regard the compound-leaved species as a separate genus, Mahonia. There are no consistent differences between the two groups other than the compound leaves, and studies suggest that the simple-leaved group is very likely polyphyletic.[1][4][5][6]" [Wiki-1]

Taxonomic Key to Mahonia

1. Leaflets usually 9-19, palmately nerved.....................................M. nervosa

1. Leaflets usually 3-11, pinnately nerved

2. Leaves more than twice as long as broad, mostly with 12-29 prominent spiny teeth; leaflets 5-11; plants 0.5-4.5 m tall.......................M. aquifolium

2. Leaves less than twice as long as broad, with 15-43 inconspicuous, spiny teeth; leaflets 3-7; plant 0.1--.6 m tall.........................M. repens


Mahonia contains 45 accepted, 61 synonym, and 46 unassessed species. [ThePlantList]

Local Species;

  1. Mahonia aquifolium - Tall Oregon-grape [E-flora][PCBC][TSFTK]
  2. Mahonia nervosa - Dull Oregon-grape [E-flora][PCBC][TSFTK]
  3. Mahonia repens - Creeping Oregon-grape [E-flora][TSFTK]

Tall Oregon-grape - Mahonia aquifolium

  • Synonyms:
    • Berberis aquifolium Pursh [E-flora-2][Turner, Kuhnlein][PFAF]
    • Berberis aquifolium var. aquifolium [E-flora-2]
    • Berberis fascicularis. [PFAF]
    • Berberis piperiana (Abrams) McMinn [E-flora-2]
    • Mahonia piperiana Abrams [E-flora-2]
    • Odostemon aquifolium (Pursh) Rydb. [E-flora-2][PFAF]
  • General: Evergreen shrub from a rhizome; stems branched, stoloniferous to stiffly erect, 0.5-2.5 (4.5) m tall; bark and wood yellowish. [IFBC-E-flora-2]
  • Leaves: Evergreen, hollylike, alternate, pinnate; leaflets usually 5-11, pinnately nerved, more than twice as long as broad, mostly with 12-29 prominent spiny teeth, shiny above but less so beneath. [IFBC-E-flora-2]
  • Flowers: Inflorescence of clustered racemes 3-8 cm long; flowers yellow, the segments in 6's. [IFBC-E-flora-2]
  • Fruits: Clustered berries 7-14 mm in diameter, blue, glaucous, with a few large seeds, edible. [IFBC-E-flora-2]
  • Habitat/Range: Mesic to dry open or closed forests in the lowland, steppe and montane zones; common in S BC; E to AB and S to ID and OR. [IFBC-E-flora-2]
  • Status: Native [E-flora-2]

Ecological Indicator Information
"A shade-tolerant/intolerant, submontane to montane, Western North American evergreen shrub distributed more in the Cordilleran than the Pacific region. Occurs predominantly in continental cool temperate and cool semiarid climates on very dry to moderately dry, nitrogen-medium soils; its occurrence increases with increasing summer drought and continentality. Sporadic in summer-dry mesothermal climates, common in open-canopy Douglas-fir forests in the coast-interior ecotone. Often associated with Agropyron spicatum, Calamagrostis rubescens, and Rhytidiadelphus triquetrus. Characteristic of moisture-deficient sites." [IPBC-E-flora-2]

Dull Oregon-grape - Mahonia nervosa

"Mahonia nervosa is an evergreen Shrub growing to 0.6 m (2ft) by 1 m (3ft 3in) at a slow rate.
It is hardy to zone (UK) 6. It is in leaf 12-Jan It is in flower from Feb to April. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Insects.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay and nutritionally poor soils. Suitable pH: acid, neutral and basic (alkaline) soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers dry or moist soil." [PFAF-1]

  • General: Evergreen shrub from a rhizome; stems branched, erect, 10-60 cm tall, leafy; bark and wood yellowish. [IFBC-E-flora-1]
  • Leaves: Evergreen, hollylike, turning reddish in the fall, alternate, pinnate; leaflets 9-19, palmately nerved, with spiny teeth. [IFBC-E-flora-1]
  • Flowers: Inflorescence of clustered racemes up to 20 cm long; flowers yellow, the segments in 6's. [IFBC-E-flora-1]
  • Fruits: Clustered berries 8-11 mm in diameter, blue, glaucous, with a few large seeds, edible. [IFBC-E-flora-1]
  • Habitat / Range: Mesic to dry open slopes and open forests in the lowland, steppe and montane zones; common in SW BC, infrequent eastward in S BC; S to CA. [IFBC-E-flora-1]
  • Origin Status: Native [E-flora-1]

USDA Flower Colour: Yellow
USDA Blooming Period: Mid spring
USDA Fruit/Seed characteristics: Colour: Blue. Present from Spring to Summer [USDA-E-flora-1]

Ecological Indicator Information

"A shade-tolerant/intolerant, submontane to montane, Pacific North American evergreen shrub. Occurs in maritime to submaritime cool mesothermal climates on moderately dry to fresh, nitrogen-medium soils; its occurrence decreases with increasing precipitation, elevation, and continentality. Scatered to abundant, occasion­ally dominant, in the understory of semi-open forests (persists on cutover sites) on water-shedding sites. Inhabits coarse-skeletal soils. Commonly associated with Gaultheria shallon, Kindbergia oregana, and Polystichum munitum. Characteristic of mesothermal forests."

  • Indicator Plants of Coastal British Columbia (Information applies to coastal locations only)[E-flora-1]

Creeping Oregon-Grape - Mahonia Repens

  • Syn:
    • Berberis amplectens (Eastw.) L.C. Wheeler
    • Berberis aquifolium var. repens (Lindl.) Scoggan
    • Berberis pumila Greene
    • Berberis repens Lindl.
    • Berberis sonnei (Abrams) McMinn
    • Mahonia amplectens Eastw.
    • Mahonia pumila (Greene) Fedde
    • Mahonia sonnei Abrams
    • Odostemon pumilus (Greene) A. Heller
    • Odostemon repens (Lindl.) Cockerell [E-flora-3]
  • General: Evergreen shrub from a rhizome; stems branched, more or less procumbent, widely stoloniferous, 15-100 cm tall; bark and wood yellowish. [IFBC E-flora-3]
  • Leaves: Evergreen, hollylike, alternate, pinnate; leaflets 3-7, pinnately nerved, less than twice as long as broad, with 15-43 inconspicuous spiny teeth. [IFBC E-flora-3]
  • Flowers: Inflorescence of clustered racemes 3-8 cm long; flowers yellow, the segments in 6's. [IFBC E-flora-3]
  • Fruits: Clustered berries 8-14 mm in diameter, blue, glaucous, with a few large seeds, edible. [IFBC E-flora-3]
  • Habitat / Range Dry rocky slopes and open forests in the steppe and montane zones; common in SE BC, rare in C and SC BC; E to AB and S to SD, TX, NM, NV and NE CA. [IFBC E-flora-3]
  • Status: Native. [E-flora-3]

Species mentioned:

Barberry, Mahonia (Berberis) [EUCp] Mahonia nervosa, aquifolium, repens, fremontii [Berries] Mahonia aquifolium, M. nervosa var. nervosa [Meuninck EWPUH]



"Of the thirteen species now recognized scattered through the country, seven occur in the records of the early uses of plants. The fruits of most were used by both the Indians and the early settlers to make a pleasantly acid drink. These berries were also used in making a tart preserve, and some of the Indian tribes dried the fruits for winter use. Probably the most important use for these plants, was in making a good yellow dye for baskets, buckskins, and fabrics." [EUCp]

Edible Uses

Other Uses

The roots, and in some cases the sterns also, were crushed and boiled to obtain the color. The bark of both Berberis repens and Berberis pinnata was used as a laxative and to make a lotion to treat various skin diseases. From the roots a bitter tonic was made which served as a blood purifier. The leaves of B. repens were boiled and the tea taken to cure general aches and rheumatic pains. [EUCp]

Medicinal Uses

Oregon grape was listed in the United States Pharmacopoeia from 1905 to 1916 and on the National Formulary from 1916 to 1937. Berberine salts are used in modern eyedrops and eye washes, and in Germany, tall Oregon grape bark extract is currently marketed for psoriasis. [Berries]
Native Americans steeped roots, stems, or bark for a tea-like infusion to use externally as a soothing wash to bathe sore eyes and as an antiseptic for skin sores. They mashed or chewed roots and stems, placing them on wounds to promote healing. Some tribes used the tea as an aperitif. [Berries]


The Navajo used Mahonia sp. to cure scorpion bite and remove bad luck.[Berries]

According to the Doctrine of Signatures-a belief that a plant's physical characteristics hinted at what disease it was good for- the yellow flowers and yellow wood indicated usefulness for treating jaundice and gallstones. A syrup of berries was given for dysentery and fevers.[Berries]

"In northern California and vicinity, the Karok used...Mahonia aquifolium, M. oreganos,... as poisons" [David E. Jones]


"Berberis spp. are rich inisoquinoline alkaloids; those in B. vulgaris include berberine, berbamine, oxyacanthine, jatrorrhizine, columbamine, palmatine, isotetrandine (berbamine methyl ether), bervulcine, and magnoflorine;1 those in B. aquifolium include aromoline, obamegine, oxyberberine, berbamine, and oxyacanthine.2" [Leung ENCI]


Roots, stems and leaves used medicinally for their berberine content. Berberine has antibiotic and analgesic properties.[Berries]

Berberine Yields

Berberine yield among individual samples ranged from 0.03 % to 0.97 %. In both species, berberine yield was greatest in the lower root, and decreased moving up the plant. There was no significant difference in berberine yield between the two species at any particular plant.[PWMP]

The season of harvest (fall or spring) had no effect on berberine yield. Likewise, there was no difference in the response between samples harvested in spring 2010 and spring 2011; while this could indicate that one-year storage does not affect berberine yield, it also may be interpreted to mean that year-to-year variation in berberine production is unlikely.[PWMP]

Our findings show that M. nervosa may have equal value to M. aquifolium, despite the preference among buyers for the latter species. More analytical testing needs to be done to confirm this. For one thing, only berberine content was analyzed; however, Mahonia species contain many other alkaloids which may be contributing factors to their bioactivity and medicinal value (Brinker 2005; Suess and Stermitz 1981).[PWMP]


The regeneration study suggests that selective harvest as opposed to complete removal of Oregon-grape plants within a given area allows for a more rapid rebound in plant cover and density. In practice, partial harvest may be more difficult to execute, since the roots of neighboring plants intermingle, causing the removal of one plant to disturb many others. Oregon-grape resprouts vigorously from root fragments, allowing for the population to regenerate following harvest. However, it is a slow-growing species, and our study did not examine how long it would take for the belowground material to regenerate to a level suitable for a second harvest.[PWMP]


M. aquifolium
  • Alterative (f; CRC; FEL; HHB; MAD); [HMH Duke]
  • Amebicide (1; CRC);[HMH Duke]
  • Anaphrodisiac (f; CRC); [HMH Duke]
  • Antialzheimeran (1; COX; FNF); [HMH Duke]
  • Antiarthritic (1; COX; FNF); [HMH Duke]
  • Antibacterial (1; DEM; FNF; WAM); [HMH Duke]
  • Antibilious (f; CRC); [HMH Duke]
  • Anticancer (1; COX; FNF); [HMH Duke]
  • Anticonvulsant (1; CRC); [HMH Duke]
  • antihemorrhagic [Leung ENCI]
  • Antihelicobacter (1; X9781854); [HMH Duke]
  • Antiinflammatory (1; COX; FNF); [HMH Duke]
  • Antimicrobial [BMWH]
  • Antioxidant (1; APA); [HMH Duke][Skidmore-Roth MHH]
  • Antiperistaltic (1; FNF); [HMH Duke]
  • Antiprolific (1; PHR); [HMH Duke] antiproliferative [Skidmore-Roth MHH]
  • Antipsoriatic (1; PHR; PH2); [HMH Duke]
  • Antipyretic (f; CRC); [HMH Duke][Leung ENCI]
  • Antiseptic (1; DEM; CRC; FNF); [HMH Duke]
  • Antitrypanosomic (1; CRC); [HMH Duke]
  • Antiulcer (1; X9781854); [HMH Duke]
  • Aquaretic (f; SHT); [HMH Duke]
  • Bitter (1; PH2); [HMH Duke]
  • cardiac relaxant [Skidmore-Roth MHH]
  • Carminative (f; CRC); [HMH Duke]
  • Cholagogue (f; CRC); [HMH Duke][BMWH]
  • Choleretic (1; CRC);[HMH Duke]
  • Collyrium (1; DEM; FNF); [HMH Duke]
  • COX-2 Inhibitor (1; COX; FNF); [HMH Duke]
  • Depurative (f; APA; CRC; DEM);[HMH Duke]
  • Digestive (1; WAM); [HMH Duke]
  • Diuretic (f; APA; CRC); [HMH Duke]
  • Expectorant (f; CRC); [HMH Duke]
  • Fungicide (1; APA); [HMH Duke]
  • Hepatotonic (1; WAM); [HMH Duke]
  • Hypotensive (1; CRC); [HMH Duke]
  • Laxative (f; CRC); [HMH Duke]
  • MDR Inhibitor (1; FNF; JAD);[HMH Duke]
  • Mutagenic (1; PH2); [HMH Duke]
  • Orexigenic (f; CRC; PH2); [HMH Duke]
  • Parasiticide (1; WAM); [HMH Duke]
  • Sedative (1; CRC); [HMH Duke]
  • Tonic(f; APA; CRC; DEM; FEL; PH2); [HMH Duke] bitter tonic [Leung ENCI]
  • Uterotonic (1; CRC).[HMH Duke]



M. nervosa; "Seed - best sown as soon as it is ripe in a cold frame[78]. It usually germinates in the spring[K]. 'Green' seed (harvested when the embryo has fully developed but before the seed case has dried) should be sown as soon as it is harvested and germinates within 6 weeks[K]. Stored seed should be sown as soon as possible in late winter or spring. 3 weeks cold stratification will improve its germination, which should take place in 3 - 6 months at 10oc. Prick out the seedlings when they are large enough to handle and grow them on in a cold frame for at least their first winter. Plant them out in late spring or early summer. Division of suckers in spring[78]. Whilst they can be placed direct into their permanent positions, better results are achieved if they are potted up and placed in a frame until established[11]. Leaf cuttings in the autumn."[PFAF-1]

Uses of Related Sp.


Page last modified on Sunday, July 11, 2021 9:27 PM