This species is closely allied to Mahonia haematocarpa and Mahonia fremontii[].
The genus Mahonia is not universally accepted. Many botanists prefer to treat it as part of Berberis - as per the Flora of N. America[]. However, although they are very closely related (and there are some intergeneric hybrids), from the point of view of the gardener they are quite distinct genera. We are therefore following the treatment in the Flora of China[] which treats them as distinct. There is, however, at least one major revision (of the Chinese genera) currently (2016) in preparation and we will review the position of Mahonia once we have seen that revision[].

Common Name:

General Information

Mahonia nevinii is an evergreen shrub growing 1 - 4 metres tall. Suckering from the base, the plant forms a dense cluster of stems with elongate primary and short or somewhat elongate axillary shoots[].
The plant is harvested from the wild for local use as a food and a medicine. It is grown as an ornamental in gardens.
The plant is known from scattered populations from San Francisquito Canyon, north of Valencia, south to Dripping Springs, near Aguanga. It is of conversation concern[].

Known Hazards

All parts of the plant contain the alkaloid berberine - this is most concentrated in the roots, stems and inner bark, and least concentrated in the fruits. In small quantities berberine has a range of effective medicinal applications but, in excess, can cause vomiting, lowered blood pressure, reduced heart rate, lethargy, and other ill-effects.
The fruit of most, if not all, members of this genus are more or less edible and can be eaten in quantity since the levels of berberine in the fruit are very low.

Botanical References

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Range

South-western N. America - southern California

Habitat

Sandy and gravelly places in sage bush scrub or chaparral[, ]. Sandy slopes and washes in chaparral, coastal scrub, and riparian scrub; at elevations up to 600 metres[].

Properties

Conservation Status	Vulnerable
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	2.40 m
Pollinators	Insects
Cultivation Status	Ornamental, Wild

Cultivation Details

Mahonia nevinii is native to semi-arid regions in the warm temperate and subtropical climate of southwestern N. America, Plants are not fully hardy in much of the temperate zone, they probably tolerate occasional temperatures down to about -10°c when fully dormant[], though the young growth in spring is more sensitive and can be damaged by temperatures falling to around 0°c.
Unlike most members of the genus, this species requires a dry, perfectly drained position in full sun[], a gritty slightly acid soil is best[]. It does well in a hot, dry position[]. Succeeds in a good garden soil[]. It grows best by a sunny south-facing wall[].
The plant hybridizes freely with other members of the genus.
Grows and flowers well at the University Botanical Gardens in Oxford[]. A plant on a south-facing wall at Kew produced a good crop of fruit in 1999[].
Plants are resistant to honey fungus[].
Some Berberis/Mahonia species (especially Berberis vulgaris) harbour the black stem-rust fungus (Puccinia graminis Persoon). This is a major disease of wheat and barley crops and can spread from infected barberries to the grain crop. The sale or transport of susceptible or untested species of Berberis is illegal in the United States and Canada[]. This species is susceptible to infection by the fungus[].

Edible Uses

Fruit - raw or cooked[]. The red fruit has an acid lemony flavour with a firm but juicy texture, it is rather nice raw, especially when added to muesli or porridge[]. Unfortunately, there is relatively little flesh and a lot of seeds[]. The fruit can be up to about 6mm in diameter[], though on specimens we have seen fruiting in Britain the fruit is only 3mm in diameter[].

Medicinal

Mahonia species have a long history of medicinal usage, with several members of the genus being commonly used in traditional medicine and also in modern herbalism. They are employed in the treatment of a wide range of conditions and have, in particular, been demonstrated to exert good efficacy in the clinical treatment of dysentery, internal and external haemorrhage, acne vulgaris and chronic pharyngitis amongst other diseases. Phytochemical research into this genus has resulted in the identification of more than 150 chemical constituents, amongst which alkaloids are predominant. The isolated compounds and crude extracts have been shown to exhibit a wide spectrum of in vitro and in vivo pharmacological effects, including antimicrobial, anti-inflammatory, hepatoprotective, antioxidant, antimutagenic and analgesic properties[]
Berberine, an alkaloid that is universally present in the rhizomes and stems of Mahonia species, has been shown to have a marked antibacterial effect[] and is also used as a bitter tonic[]. Since it is not appreciably absorbed by the body, it can be used orally in the treatment of various enteric infections, especially bacterial dysentery[].
Berberine has also shown antitumour activity[].
The plant should not be used with Glycyrrhiza species (Liquorice) because this nullifies the effects of the berberine[].

Other Uses

A green dye is obtained from the roots[].
Dark green, violet and dark blue-purple dyes are obtained from the fruit[].
A green dye is obtained from the leaves[].

Propagation

Seed - best sown as soon as it is ripe in a greenhouse[]. It usually germinates in the spring[]. '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[]. 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 10°c. Prick out the seedlings when they are large enough to handle and grow them on in the greenhouse for at least their first winter. Plant them out in late spring or early summer and consider giving them some protection from the cold for their next winter.
Division of suckers in spring[]. 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[].
Leaf cuttings in the autumn.