Description and biology
Nevin’s barberry is a large evergreen shrub with blue-green, spiny leaves, bright red edible berries, and bright yellow flowers that bloom March through April.
It is a rhizomatous plant (pronounced RYE–zoe–mat–us; a plant having an underground horizontal stem that puts out shoots above ground and roots below) that measures from 3 to 12 feet (1 to 4 meters) in height.
The leaves are pinnate, meaning they are arranged on opposite sides of the stem like feathers. The flowers are clustered, with six petals in two rows. The tiny, juicy berries are about 0.3 inches (6 to 8 millimeters) long.
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Habitat and current distribution
Nevin’s barberry is found in sandy or gravelly areas or in washes at altitudes ranging between 900 and 2,000 feet (300 and 650 meters) in chaparral habitats of the interior foothill region of southern California. The two largest populations of Nevin’s barberry, together containing about 200 individual plants, are found near Vail Lake in southwestern Riverside County.
Another large population occurs in San Francisquito Canyon in the Angeles National Forest in Los Angeles County. Beyond these three populations, there are some isolated populations in San Bernardino and Los Angeles Counties.
History and conservation measures
The range of Nevin’s barberry has always been limited to specific areas of southern California, and scientists believe it has always consisted of fewer than 30 scattered populations. At least seven former populations have become extinct.
The biggest threat to these plants is urbanization, or the building of commercial and residential developments, within their small and specific range. The species requires certain kinds of soil, rock, and moisture, and a chaparral community of plants, to survive.
It has been estimated that about 90 percent of the required habitat for this species has been eliminated by urban development, which includes building construction, road construction, flood control systems, and recreational activities, such as the use of off–road vehicles. Southwestern Riverside County developed at a very rapid pace and the Vail Lake area itself became a developing community in the 1990s.
Land-owners whose property contains Nevin’s barberry populations are likely to put in gardens and lawns, which will fragment the surviving populations and introduce nonnative plants to their habitat.
The necessary fire management in areas developed for human residence and commerce is not like the natural fire cycles for which chaparral communities are adapted. There are no national recovery plans in place for the species, although research continues.
