Santa Cruz Island Fringepod

Thysanocarpus conchuliferus

Description

The Santa Cruz Island fringepod, also known as the Santa Cruz Island lacepod, is a small, delicate, annual herbaceous plant. It has one to several branches, and grows 2-5 in (5-13 cm) tall. Its narrow, linearly lobed leaves are arranged in alternate fashion along the stems, which have a terminal inforescence (or raceme) of minute, pink to lavender flowers. The Santa Cruz Island fringepod is distinguished from other species in the genus Thysanocarpus in having a bowl-shaped fruit (rather than a round, flattened fruit with wings).

Habitat

The Santa Cruz Island fringepod occurs on rocky outcrops on ridges and canyon slopes, and is associated with a variety of native species of herbs, ferns, grasses, and other plants.

Distribution

The Santa Cruz Island fringepod is a locally evolved (or endemic) plant that is only known from Santa Cruz Island, in the coastal Pacific Ocean off southern California. Santa Cruz Island is the largest of the California Channel Islands at 96 sq mi (249 sq km), with the highest point being 2,470 ft (753 m) above sea level.

Threats

The Santa Cruz Island fringepod is known from 14 historical locations on Santa Cruz Island. In 1991, however, the species only occurred at six of those locations, and in 1993, no individuals were found at any of the known habitats. As of 1997, no verifiable observations of this endangered species had been made for more than two years. The apparent demise of the Santa Cruz Island fringepod appears to have been caused by severe habitat damage resulting from the rooting activities of introduced feral pigs, including soil loss, habitat alteration, and direct predation of the rare plants. In addition, the endangered fringepod plant has suffered from excessive competition with alien plants, especially species of grasses and the fennel (Foeniculum vulgare ). If it still survives, the Santa Cruz Island fringepod exists as tiny, isolated populations that are extremely vulnerable to extinction caused by severe disturbances, such as an extreme weather event (e.g., a hurricane). It may also be vulnerable to reduced reproductive vigor due to inbreeding.

Conservation and Recovery

The western 90% of Santa Cruz Island is owned and managed by The Nature Conservancy (TNC), a private conservation agency. The other 10% of the island is Federal land managed by the National Parks Service. Thus, all of the habitat of the Santa Cruz Island fringepod is being conserved for its natural values. Nevertheless, the critically endangered plant remains threatened by the feeding activity of feral pigs, and by invasive alien plants. Extensive surveys must be made of all of the known and likely habitats of the Santa Cruz Island fringepod, to determine whether it might still survive. The feral population of pigs on Santa Cruz Island must be eradicated, an action that would benefit other endangered species of plants and animals in addition to the fingepod. The abundance of alien plants must also be decreased.

Contact

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 Field Office
2493 Portola Road, Suite B
Ventura, California 93003-7726
Telephone: (805) 644-1766
Fax: (805) 644-3958

Reference

U. S. Fish and Wildlife Service. 31 July 1997. "Endangered and Threatened Wildlife and Plants: Final Rule for 13 Plant Taxa From the Northern Channel Islands, California." Federal Register 62 (147):40954-40974.