Ben Lomond Wallflower

Erysimum teretifolium

Description

Ben Lomond wallflower, Erysimum teretifolium, is a biennial, or occasionally an annual, plant of the mustard family. Seedlings form a basal rosette of leaves, which wither as the main stem develops flowers clustered in a terminal raceme. The flowers are a deep yellow with petals of 0.5-1 in (1.3-2.5 cm) long; the slender capsule reaches 4 in (10 cm) in length and is covered with three-parted hairs. The leaves are simple and narrowly linear, a characteristic that separates this plant from other wall-flowers.

Habitat

Ben Lomond wallflower is endemic to pockets of sandstone deposits in the Santa Cruz Mountains and was known at the end of the twentieth century from only a dozen scattered occurrences. These sandstone deposits support the unique ponderosa pine sandhill community, and Ben Lomond wall-flower seems to prefer sites with loose, uncompacted sand in openings between scattered chaparral shrubs. Another endangered plant, the robust spineflower (Chorizanthe robusta var. robusta ) is found in close proximity at some locations.

Distribution

Ben Lomond wallflower was first collected in Santa Cruz County by Horace Davis in 1914. It was spread throughout the sandstone deposits of the Santa Cruz Mountains.

Ben Lomond wallflower is endemic to pockets of sandstone deposits in the Santa Cruz Mountains and in the late 1990s was known from only a dozen scattered occurrences within the area generally bounded by the communities of Ben Lomond, Glenwood, Scotts Valley, and Felton, with one outlying population occurring in the Bonny Doon area 5 mi (8 km) west of Felton. One population occurred at Quail Hollow Ranch, which was jointly owned by Santa Cruz County, the Nature Conservancy, and the California Department of Fish and Game. All other populations were on privately owned lands.

The largest population of Ben Lomond wall-flower—about 5,400 individuals as of 1986—was at the Quail Hollow Quarry. This represented 75% of the surviving individuals. Quail Hollow Ranch supported less than 300 individuals. Of the remaining populations, none comprised more than 400 individuals and about half totaled less than 100 individuals each. The population at Bonny Doon Ecological Reserve fluctuated wildly. In 1982 there were about 1,000 individuals but by 1986 there were only about 25. The population was thriving in 1994 but by 1997 there were only 28 plants.

Threats

Three endangered species—Ben Lomond wall-flower (E. teretifolium ), Ben Lomond spineflower (C. pungens hartwegiana ), and robust spineflower (C. robusta )—are restricted to sandstone and mudstone soils in the Santa Cruz Mountains. These species and their associated habitats are threatened by one or more of the following: residential and golf course development; agricultural land conversion, recreational use, sand mining, dune stabilization projects, and military activities. The proposed expansion of operations of the Quail Hollow Quarry may eliminate additional populations.

Alteration of Ben Lomond wallflower habitat may also be occurring in the form of increased canopy density within the Ben Lomond sandhills as a result of fire suppression. The suppression of wild-fires caused the density of woodland and the pine sandhill community to increase, which may reduce the availability of suitable habitat for the wallflower.

Conservation and Recovery

Small populations of Ben Lomond wallflower occur on the Bonny Doon Ecological Preserve, managed by the Nature Conservancy, but as of 2000 no managerial plans had been developed to protect the species.

Contacts

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

U.S. Fish and Wildlife Service
Ventura Fish and Wildlife Office
2493 Portola Rd., Suite B
Ventura, California 93003-7726
Telephone: (805) 644-1766

Reference

U.S. Fish and Wildlife Service. 4 February 1994. "Determination of Endangered Status for Three Plants and Threatened Status for One Plant from Sandy and Sedimentary Soils of Central Coastal California." Federal Register 59 (24): 5499-5511.