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categoryZBroadleaf Broadleaf List 
categoryZEvergreen Evergreen List 

OREGON-GRAPE

Mahonia aquifolium

(Formerly: Berberis aquifolium)
Barberry Family [Berberidaceae]

Flowers:
month8mar month8apr month8may month8jun month8jul month8aug month8sep month8oct

Berries: dull: berryZgreen berryZred berryZpurple berryZbluish berryZblack    Vit. C, edible, astringent
month8april month8may month8jun month8jul month8aug month8sep month8oct

category
category8Shrubs
category
category8Broadleaf
category
category8Evergreen
status
statusZneophyte

flower
flower8yellow
 
morph
morph8actino
 
petals
petalsZ6
(4 + 2)
type
typeZspiked
 
type
typeZbell
 
stem
stem8round
 
stem
stem8milkysap
yellow
smell
smell8scente
scented
contact
contactZmedium
spines
sex
sexZbisexual
 

30th June 2016, railway line fence, Freshfield, Sefton Coast. Photo: © RWD
It grows to 1.5m high, this specime barely reaching 70cm ascending beside a wire fence guarding the railway line.


30th June 2016, railway line fence, Freshfield, Sefton Coast. Photo: © RWD
Oregon-Grape starts to flower in April. By Novemember, if not well before, the berries start to develop, and ripening by February or so. Ripe berries are blue-black but with a frosty sheen which rubs off when handled.


30th June 2016, railway line fence, Freshfield, Sefton Coast. Photo: © RWD
The berries are round when ripe and bluish-black beneath the paler sheen which easily rubs off, as can be espied in the photo. They contain large seeds. The sepals are in two stacked layers of 3 + 3, the lower set slightly larger than the upper set.


30th June 2016, railway line fence, Freshfield, Sefton Coast. Photo: © RWD
The leaves are glossy(ish) on the upperside and have between 5 to 15 short teeth or spines on each side. Moreover, the teeth are not alternately pointing up and down as they are on some of the other Oregon-grapes. The berries are not grapes, despite the name Oregon-grape. The berries are quite sharpish to the taste containing only smaller quantities of glucosides.


30th June 2016, railway line fence, Freshfield, Sefton Coast. Photo: © RWD
Paler leaf veins criss-cross the upper surface, but the surface is flat rather than bullate, but is leathery.


30th June 2016, railway line fence, Freshfield, Sefton Coast. Photo: © RWD
Leaflets in opposite pairs with a single leaflet at the tip. This is the matte paler-green obverse side.


30th June 2016, railway line fence, Freshfield, Sefton Coast. Photo: © RWD
Short spines as leaf teeth. On Mahonia aquifolia, the spines number between 5 and 15 on each side.


17th April 2015, roadside, nr. Aldford, deepest Cheshire. Photo: © RWD
This specimen from Aldford has fewer leaf teeth, and may, or may not, be a cultivar, of which there are many. However the flowers are small and similar enough to the real McCoy to be used as the photo to show the flowers. The flowers are smallish and in tight clusters, globular before opening and are scented.


17th April 2015, roadside, nr. Aldford, deepest Cheshire. Photo: © RWD
The flowers are yellow and it is claimed by one source they have 6 bright-yellow petals in a 4 + 2 arrangement surrounded by 6 conolorous sepals (which may be similarly arranged?). No doubt they vary somewhat when looking at a hybrid or cultivar.




A CULTIVAR

24th March 2012, Leeds & L/pool canal, Wigan, Lancs. Photo: © RWD
The leaf teeth are few and below the 5 each side considered as the lowest number for Mahonia aquefoilium. The developing fruit are also on longish racemes, so your Author thinks this is one of the many cultivars.


24th March 2012, Leeds & L/pool canal, Wigan, Lancs. Photo: © RWD


24th March 2012, Leeds & L/pool canal, Wigan, Lancs. Photo: © RWD


24th March 2012, Leeds & L/pool canal, Wigan, Lancs. Photo: © RWD


24th March 2012, Leeds & L/pool canal, Wigan, Lancs. Photo: © RWD


24th March 2012, Leeds & L/pool canal, Wigan, Lancs. Photo: © RWD
The stems have a toxic yellowish sap within, as do other Berberidaceae species, of which Oregan-grape is a member.


24th March 2012, Leeds & L/pool canal, Wigan, Lancs. Photo: © RWD
The fruit eventually turns blackish-blue and becomes almost globular, but this specimen is probably a cultivar with oblong fruit.


24th March 2012, Leeds & L/pool canal, Wigan, Lancs. Photo: © RWD






ANOTHER CULTIVAR

27th Dec 2016, a garden, Hebden Bridge, West Yorkshire. Photo: © RWD
One of the cultivars with long spikes of yellow flowers.


27th Dec 2016, a garden, Hebden Bridge, West Yorkshire. Photo: © RWD
There are at leasst 17 leaflets to the leaves, at least 2 more than the specification for Mahonia aquefoilum, so this is one of the cultivars. It also has fewer leaf teeth than the 5 to 15 specified for Mahonia aquefoilum.


Easily confused with : Flower () [plants with similar names belonging to differing families]

Mahonia should not to be confused with : Ammonia (NH3) [a poisonous gas with similar sounding name]

The pure Oregon-grape, (Mahonia aquifolium), grows to 1.5m
Leaves shiny on upperside
Leaflets (3) 5 - 9, 3 to 8cm long, c. half as wide
Leaf teeth 5 - 15 small spines on each side

Some hybrids between this and other Mahonia species which do not occur in the UK - such as the hybrid with Mahonia pinnata (Mahonia × wagneri) called Wagner's Oregon-grape can grow higher, up to 2.5m.
Leaves dull on upperside
Leaflets 5 - 9, 5 to 10cm long, c. half as wide
Leaf teeth 4 - 7 spines on each side

Or the hybrid with Mahonia repens] (Mahonia × decumbens) called Newmarket Oregon-grape is much shorter at just up to 0.5m and is decumbent; sprawling along the ground.
Leaves dull on upperside
Leaflets 5 - 7, unspecified length!, more than twice as long as wide
Leaf teeth 8 - 22 small spines on each side

There also exist several cultivated varieties with leaves which are shinier, or with leaves with much more leaflets, or with larger spiines on the edges of the leaves, or which grow far higher (up to 5m)!

Uniquely identifiable characteristics

Distinguishing Feature :

No relation to : Oregon Maple (Acer macrophyllum) [A tree with similar name].

A toxic yellow-orange dye can be extracted from the bark and woody stems, possibly containing Berberine or similar substances.


  Mahonia aquifolium  ⇐ Global Aspect ⇒ Berberidaceae  

Distribution
 family8Barberry family8Berberidaceae
 BSBI maps
genus8Mahonia
Mahonia
(Oregon-Grapes)

OREGON-GRAPE

Mahonia aquifolium

(Formerly: Berberis aquifolium)
Barberry Family [Berberidaceae]