by Karen J. Albins, Native Plants Class 2003
Common names: Frémont mahonia, Frémont's barberry, bérbero, agracejo, palo amarillo
Family: Berberidaceae
Synonymy: Berberis fremontii Torr., Berberis higginsiae Munz, Mahonia higginsiae (Munz) Ahrendt, Odostemon fremontii (Torr.) Rydb.
Etymology: The epithet fremontii refers to General John Charles Frémont (1813-1890), the leader of two expeditions to California and the first botanical collector in the Sierra Nevadas (2).

Identification
Growth form: Frémont mahonia is an erect shrub 1-3 m tall with rigid branches.
Roots:
Stem: Stems are woody and yellow, with yellow inner bark.
Leaves: Leaves are pinnately compound with 3-7 leaflets (2.5-7 cm long, 1-4 cm wide). Leaflets are evergreen, thick, leathery, and have wavy margins with approximately 3 large teeth ending in very sharp prickles.
Inflorescence/flowers: Inflorescences are subcorymbose clusters of 3-9 perfect, regular, yellow flowers with 6 petals, sepals, and stamens and 1 pistil. The one-celled ovary is superior. Flowers are very fragrant.
Fruit: The fruit is a few-seeded berry that is blue or blue-black in color and dry at maturity.
Similar species: Berberis wilcoxii Kearney is a rare straggling shrub with a racemose inflorescence and ovoid berries (as opposed to subcorymbose clusters and globose berries in M. fremontii). In our area there is only one known population of B. wilcoxii found in Yavapai County at 5000 feet (6). Mahonia haematocarpa (Woot.) Fedde is an erect shrub found at lower elevations in Arizona (below 4500 feet) (2). It can be distinguished from Mahonia fremontii by the presence of a long terminal leaflet that is 2-5X long as wide and by its red, juicy berries. The terminal leaflet of Mahonia fremontii is not more than 2X as long as it is wide.

Ecology
Life history: Perennial
Native/introduced: Native
Photosynthetic pathway: other members of genus are C3 (5)
Phenology: In northern Arizona, mahonia flowers from May to June (6). Fruits are disseminated from July to October.
Distribution: Southwestern United States in Arizona, California, Colorado, New Mexico and Utah from 4000-7000 feet in well-drained soils (2). In Arizona Frémont mahonia is found in Apache County to eastern Mohave and northern Yavapai Counties in pinyon-juniper woodlands from 4000-7000 feet in elevation (4,6).

Uses
Wildlife: There are no references of wildlife use for this plant, but related plants are known to have little forage value and are sometimes poisonous to livestock (4). Berries of related plants provide food for birds and small mammals (2).
Human: The Southern Paiute Indians ate the berries of Frémont mahonia and sometimes ground them into a mush (1). The berries also make excellent jams and jellies (2). Extracts from the plant contain the drug berberine, and the roots were sometimes used to create a bitter tonic (2,3). The Hopi have used Frémont mahonia wood for crafts, and the roots can be boiled to create a yellow dye (3). Frémont mahonia is a secondary host for a cereal crop pathogen and is not used as an ornamental for this reason (4).

References
1. Dunmire, W.W. and G.D. Tierney. 1997. Wild Plants and Native Peoples of the Four Corners. Museum of New Mexico Press: Santa Fe, NM. 312 pp.

2. Elmore, Francis H. 1976. Shrubs and Trees of the Southwest Uplands. Southwest Parks and Monuments Association: Tucson, AZ. 214 pp.

3. Epple, A.O. 1995. A Field Guide to the Plants of Arizona. Falcon Press: Helena, MT. 347 pp.

4. Kearney, T.H. and R.H. Peebles. 1964. Arizona Flora. University of California Press: Berkeley, CA. 1085 pp.

5. Krenzer, E.G., D.N. Moss and R.K Crookston. 1975. Carbon dioxide compensation points of flowering plants. Plant Physiology 56: 194-206.

6. McDougall, W.B. 1973. Seed Plants of Northern Arizona. Museum of Northern Arizona: Flagstaff, AZ. 594 pp.