Scientific: Berberis trifoliata (also known as Mahonia trifoliata)
Common: desert barberry, desert mahonia, Agarita mahonia
Family: Berberidaceae
Origin: Southwest North America desert to grassland transitions zones between 3,000 and 7,000 feet elevation.

Pronounciation: BER-ber-is tri-fol-ee-A-ta

Hardiness zones
Sunset
7-9, 12-13
USDA 8 - 11

Landscape Use: Best used in desert landscape gardens with high diversity and mixed greenery as a filler plant, textural accent.

Form & Character: Upright, stiff and spikey, unfriendly, alone, non-conformist, dangerous.

Growth Habit: Basally spreading evergreen shrub to 5 feet in height with similar to lesser spread.

Foliage/texture: Three lobed, nearly pinntified, strongly serrate and leathery leaves, grayish green in color, nearly sessile; medium coarse texture.

Flowers & fruits: Simple clusters of small yellow, axillary, 6-petaled flowers in spring followed by fruits that are small, dark, bluish black drupes in late fall and winter.

Seasonal color: None

Temperature: Very tolerant of desert conditions.

Light: Full sun to partial shade.

Soil: Very tolerant.

Watering: Little additional water from irrigation after establishment.

Pruning: Use heading cuts once per few years to encourage fullness and a natural form - I recommend either early spring or early fall in Phoenix. Cut back to any height to select desired mature size after regrowth. Shearing a desert barberry is a surefire way of demonstrating horticultural naivety.

Propagation: Fresh seed propagation, vegetative stem cuttings, tissue culture, micropropagation.

Disease and pests: None

Additional comments: Desert barberry is a seldom used southwest native shrub. The genera Berberis and Mahonia are often confused and combined; some taxonomist consider them to be the same while others differentiate.

Additional notes: The genus Berberis has many antibacterial, antitumor, and tonic medicinal uses. Berberine, universally present in rhizomes of Berberis and Mahonia species, has marked antibacterial effects and is used as a bitter tonic. Since it is not appreciably absorbed by the body, it is used orally in the treatment of various enteric infections, especially bacterial dysentery. For highest concentrations, the root and root bark are best harvested in the autumn. Plants in the family Berberidaceae all have high concentrations of xanthophyll (yellow) pigmentation in the stem. A yellow dye is obtained from the inner bark of the stem and roots. An ink is made from the wood. Dark green, violet and dark blue-purple dyes are obtained from the fruit. A green dye is obtained from the leaves.