Menzies' Wallflower

Erysimum menziesii

Description

The Erysimum menziesii (Menzies' wallflower) is a low growing, succulent, rosette-forming, biennial to short-lived perennial herb. This species usually produces dense clusters of bright yellow flowers in the winter and early spring. However, it may also flower in the early summer. The Menzies' wall-flower is distinguished from related species by its fleshy spoon-shaped leaves that grow in a rosette, divergent fruits or siliques, and small consistently yellow petals. The Menzies' wallflower reproduces by seed, and its seeds are dispersed by wind. It germinates after the first rains in fall or early winter. The vegetative rosette stage of the life cycle can continue for up to eight years, and flowering may depend on rosette size. The pollinators are thought to be bees, bumblebees, butterflies, and moths. The wallflower can set fertile seed through self pollination, so it reproduces both by selfing and through outcrossing.

The three endangered subspecies of Erysimum menziesii are distinguished as follows: Erysimum menziesii ssp. menziesii has flower stalks 1.2 to 3.5 in (3-9 cm) to tall, and the longest fruits are usually less than 3.1 in (8 cm) long, whereas Erysimum menziesii ssp. eurekense has flower stalks 0.4-0.6 in (1-1.5 cm) tall, and the longest fruits are usually more than 3.1 in (8 cm) in length. The leaves of Erysimum menziesii ssp. menziesii are generally lobed or irregularly toothed and the flowers are rich yellow. Erysimum menziesii ssp. eurekense is distinguished from the other subspecies by its more toothed (dentate) leaves, longer stems, and longer narrower fruits. Also, the leaves are less fleshy than those of Erysimum menziesii ssp. menziesii, and the flowers of ssp. eurekense are light yellow. Erysimum menziesii ssp. yadonii differs from the other subspecies because it blooms in summer (June-August), whereas the other subspecies bloom in winter or spring. It tends to be perennial with a branched caudex. The flower petals are rich yellow.

Habitat

The Menzies' wallflower is restricted to the coastal foredune and coastal dune scrub communities and associated habitats occupied by coastal scrub or coastal terrace prairie. These are isolated occurrences within wind-sheltered, sparsely vegetated areas. The wallflower is associated with the California Coastal Redwood Belt, which occurs in the Siskiyou-Trinity Area, in Central California Coastal Valleys and the Central California Coast Range. Broadly, these regions have an elevation from sea level to 3,100 ft (900 m); average annual precipitation of 12-85 in (35-215 cm) distributed throughout the year; perennial streams and lakes distributed throughout the regions and glacial and alluvial deposits in the valley that yield large quantities of water; and soils that are well drained on gently sloping to very steep slopes. The erosion hazard is high and is stabilized only by plant cover.

Distribution

Menzies' wallflower is discontinuously distributed within the coastal foredune community of four dune systems within Humboldt Bay, Humboldt County, the Ten-mile River dune system and Monterey Bay dune system in Mendocino County, and the Monterey Peninsula dune system. This species occupies lands owned by The Nature Conservancy and the State of California. There are about 16 surviving populations, with 33,300 individuals.

Threats

The habitat of the Menzies' wallflower in the California coast dune scrub communities is threatened by a number of factors including: invasion of alien plants, proposed commercial and residential development, military operational uses, off-road vehicle damage, and trampling by equestrians, hikers and livestock. Potential threats include sand mining, disposal of dredged material from adjacent bays and waterways, and stochastic extinction due to depauperate numbers. The construction of a golf course in 1987 near Spanish Bay on the Monterey Peninsula eliminated a significant portion of a population. The developer attempted to mitigate for the project by transplanting this subspecies to an artificial dune, but this was not successful.

Much of the habitat of the Menzies' wallflower has been degraded by invasive, non-native plants. In the dune systems north of Monterey Bay, sand-stabilizing rhizomatous grasses (especially Ammophila arenaria and Elymus mollis ) generally dominate the vegetation of the foredunes. Ammophila arenaria (European beach grass or marram grass) is an alien that has largely replaced the native Elymus-dominated foredune community. Beach grass is a powerful geomorphic agent due to its ability to build wall-like foredunes, which were not previously in this region. Although the Elymus-dominated foredune community exists around Monterey Bay, these foredunes typically consist of low hillocks and mounds that are sparsely populated with generally succulent, tap-rooted perennial herbs. The stabilization of the dunes by Ammophila arenaria has permitted the colonization of formerly active backdune areas with a mixture of native and alien plants. These backdune areas consist of a soft, woody, dense plant community of short shrubs and subshrubs, and herbaceous plants. These habitat changes are severely threatening to the Menzies' wallflower and other native plants. The wallflower has been eliminated from all but a small fraction of its historical dune or associated habitats. Today, the Menzies' wallflower persists only as small "island" populations surrounded by urban areas, roads, trails, agricultural lands, competing alien plants, and other hostile habitats.

Conservation and Recovery

The Menzies' wallflower occurs on federally and state-owned lands, but is threatened there by incompatible land-use activities. For example, populations within Salinas River State Beach are subject to trampling by off-road vehicles, hikers, and equestrians. However, the remnant population within Asilomar State Beach is on a steep bluff face, inaccessible to the public.

Menzies' wallflower habitat at Lanphere Dunes (in the Humboldt Bay Refuge managed by the Fish and Wildlife Service) is managed by controlling exotic plants. European beachgrass has been eliminated from the preserve, although not from the dune system. The management of the preserve has been so successful that there has been a significant increase in Menzies' wallflower populations. Fore-dunes at the preserve will continue to recolonize with beachgrass and will require follow-up until the entire beach area between headlands is cleared of beachgrass propagules. The Menzies Wall-flower Research Program, funded by Louisiana-Pacific Corporation and Simpson Timber Company, has resulted in the development of habitat management measures that include removal of non-native plants, restoration, and habitat protection activities. A study of the demographics and genetics of the subspecies was funded by the National Science Foundation and conducted by Michigan State University and The Nature Conservancy.

The Bureau of Land Management (BLM) also has restoration projects to reduce the threat of non-native plants. The BLM has fenced 40 acres (16 hectares) of Menzie's wallflower habitat to protect itfrom off-road vehicle use on the Samoa Peninsula. The BLM has funded a restoration program and developed a strong volunteer program to provide for weed removal on the Manila and Samoasites. The BLM secured a grant from the National Fish and Wildlife Foundation and internallyfunded a national Parmers Against Weeds Initiative to remove European beachgrass from the Humboldt Bay Dunes and the Manila Dunes Area of Critical Environmental Concern and Research Natural Area. Continued financial support for dune restoration and maintenance will be essential to recover the species.

For occurrences of Menzie's wallflower on lands in the Cities of Marina and Pacific Grove, implementation of the cities' Land Use Plan should protect and restore native dune habitat and vegetation, and the habitat of rare and endangered species. The cities' policies specify that primary habitat areas for sensitive species be protected and preserved. Development within secondary or support habitat areas is allowed, if it does not significantly impact primary habitat areas. Where development is proposed on parcels containing rare and endangered species, parcel owners are required to develop and execute a management plan that will protect the identified plant species.

At MacKerricher State Park, habitat of the Menzie's wallflower was revegetated after an archaeological dig. Some habitat of the Menzies' wall-flower is on privately owned land, and is threatened by commercial and residential development. These critical habitats should be protected. This could be done by acquiring the private land and establishing ecological reserves, or by negotiating conservation easements with the landowners. The populations of the Menzies' wall-flower should be monitored, and research undertaken into its biology and habitat needs, particularly with regard to management practices that would decrease the influence of invasive non-native plants. More of its habitat should be managed to reduce the abundance and ecological effects of alien plants.

Contacts

U. S. Fish and Wildlife Service
Sacramento Fish and Wildlife Office
2800 Cottage Way, Room W-2605
Sacramento, California 95825-1846
Telephone: (916) 414-6600
Fax: (916) 460-4619

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Building Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
http://pacific.fws.gov/

References

U.S. Fish and Wildlife Service. 22 June 1992. "Six Plants and Myrtle's Silverspot Butterfly From Coastal Dunes in Northern and Central California Determined to Be Endangered." Federal Register 57 (120): 27848-27858

U.S. Fish and Wildlife Service. 1998. "Seven Coastal Plants and the Myrtle's Silverspot Butterfly." U.S. Fish and Wildlife Service, Portland, Oregon.