Ben Lomond Spineflower

Chorizanthe pungens var. hartwegiana

Description

Ben Lomond spineflower, Chorizanthe pungens var. hartwegiana, is a small and wiry annual herb that grows up to 10 in (25 cm) high. It has mediumsized dark pink to purple flowers growing in a dense cluster. The inner and outer petal-like sepals (green coverings of the flower) are equal in length and are lobed rather than fringed. The flower's filaments are free, and there are three to nine stamens. There are six bracts below the flowers: three are toothed with the alternating three shorter. The shrubs can grow along the ground or erect, covered with short hairs.

Ben Lomond spineflower is short-lived. Seeds germinate in the late fall after the first substantial rains. The plants mature through the winter and then bolt and produce branches. They flower in April and May, then die soon after seed production in June. The life span ranges from 15-21 weeks, with most of the vitality coming during the adult stage. The plants are pollinated by a variety of insects, including wasps, bees, flies, and butterflies.

Habitat

Ben Lomond spineflower is found—mostly on privately owned land—on sandy soils that are the basis for the Ben Lomond sandhill communities in the Santa Cruz Mountains. It is confined to outcrops of sandstone soils that support several unique plant communities, including the ponderosa pine. It is frequently found in association with Ben Lomond wallflower (Erysimum teretifolium ), and grows best in unshaded conditions. Highest seed sets have been observed in open pine forests. Plants growing in full sun flower earlier than those in low or high shade. Plants in low shade, however, produce more flowers than those in full sun. Research has concluded that Ben Lomond spineflower will grow in soil types other than sandy soils, but that its intolerance of shade draws it to sandy soil types.

Distribution

It was not until 1969 that James Reveal and Clare Hardham distinguished Ben Lomond spineflower from Ben Lomond wallflower, another endangered species. Ben Lomond wallflower was widely spread throughout the sandy soils of coastal habitats in southern Santa Cruz and northern Monterey Counties.

Most occurrences of Ben Lomond spineflower are found in the area generally bounded by the communities of Ben Lomond, Glenwood, Scotts Valley, and Felton. Outlying populations are located near Bonny Doon, Boulder Creek, Big Basin State Park, and Gray Whale Ranch State Park.

Threats

Among the threats facing this species are golf course development, agricultural land conversion, recreational use, sand mining, and military activities. At least half of the habitat occupied by Ben Lomond spineflower is on land owned by sand and gravel companies. Populations located on land owned by the San Lorenzo Valley Water District were badly damaged by off-road vehicles despite efforts to fence off the area.

Sand quarrying resulted in the direct removal of the Ben Lomond spineflower, and a proposed expansion of operations of Quail Hollow Quarry may eliminate additional populations. Residential development on smaller parcels of privately owned lands have also contributed to the elimination of the species and the fragmentation of the remaining habitat.

Conservation and Recovery

Protective management for sandhill parkland communities will be developed for one parcel of the Ben Lomond spineflower's habitat recently acquired by the State of California. Quail Hollow Ranch, which supports the largest population, was recently acquire by Santa Cruz County and the State of California. Management plans for Quail Hollow Ranch are under development, and recreational facilities may adversely affect the populations.

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.