Pitkin Marsh Lily

Lilium pardalinum ssp. pitkinense

Description

Lawrence Beane and Albert M. Vollmer first collected Lilium pardalinum ssp. pitkinense (Pitkin Marsh lily) on July 20, 1954, in Sonoma County, California. Beane described the plant as L. pitkinense the following year. Mark Skinner subsequently treated the plant as a subspecies of L. pardalinum in 1993.

L. pardalinum ssp. pitkinense is an herbaceous, rhizomatous (underground stem) perennial in the lily family (Liliaceae). The slender, erect stems reach 3-6 ft (1-2 m) in height. Leaves are yellow-green, up to 5.5 in (14 cm) long, and 0.4-0.8 in (1-2 cm) wide. The leaves are generally scattered along the stem, but in some plants occur in two or three whorls of three to six leaves near the middle of the stem. The inflorescence is a terminal raceme. The flowers are large, showy, and nodding. The petals, which are reflexed from the middle, are red at the outer edge and change to yellow at the center with small, deep maroon dots mostly within the yellow zone. Anthers, the pollen-bearing part of the stamen, are purple-brown. The fruit is an elliptical capsule containing many rounded seeds. The species flowers from June to July. L. pardalinum ssp. pitkinense is distinguished from L. pardalinum ssp. pardalinum by generally shorter petals and anthers.

Habitat

L. pardalinum ssp. pitkinense grows only in permanently saturated, sandy soils in freshwater marshes and wet meadows that are 115-200 ft (35-60 m) in elevation.

Distribution

Only three populations of L. pardalinum ssp. pitkinense at two sites were recorded historically. All three populations are on private land within a distance of 8 mi (13 km) in Sonoma County. Access to one of the sites has been denied by the landowner since 1975; as a result, the status of this population has not been confirmed, although it is presumed to be extant. Two populations occur at a second site. The size of these populations has declined due to loss of habitat from urbanization and competition with blackberries. About 300 individual plants remain on these two sites.

Threats

L. pardalinum ssp. pitkinense is threatened by prior habitat destruction and potential disturbance from a proposed subdivision; uncontrolled collection of plants, seeds, and bulbs for horticultural use; competition from invasive plant species; trampling and herbivory by livestock and wildlife; and destructive random events. An operating wastewater treatment plant could potentially threaten one population of this taxon.

One site with two populations of L. pardalinum ssp. pitkinense was largely destroyed by urbanization in 1961, but approximately 300 plants remain at this location. Although a subdivision is planned for the area surrounding a portion of this site, the landowner agreed to protect a portion of the habitat of this taxon. This agreement, if implemented, would place all sensitive natural resource areas in a conservation easement for long-term management with the California Department of Fish and Game (CDFG) as easement holder. Neither this easement, however, nor another easement that would protect the other population of L. pardalinum ssp. pitkinense at this site has been executed and recorded. Wet-land fills in the marsh have lowered the water table at this second location, resulting in drier soil conditions harmful to the L. pardalinum ssp. pitkinense there; since only about 10 plants remain, this change in habitat quality is a very significant threat to the population.

One of the remaining populations of L. pardalinum ssp. pitkinense has been nearly extirpated by uncontrolled collection of plants, seeds, and bulbs for horticultural use. This species was abundant historically at this site, but the removal of plants and bulbs for horticultural purposes reduced this population to two plants by 1993, a total that rose to about 10 by the late 1990s. Similar activities at the remaining site, which contains only 300 individuals in two populations, would likely result in the extinction of the species.

Populations of this taxon have been enclosed with various types of wire fencing in an attempt to prevent grazing or browsing by cattle, horses, and deer, but most of the fences have failed to prevent grazing completely. The plants continue to suffer from herbivory by cattle, deer, gophers, and possibly other herbivores, resulting in loss of flowers and seeds.

Because L. pardalinum ssp. pitkinense is unlikely to be self-pollinating, single plants or widely separated plants in sparse populations may not set viable seed. The remaining plants at one site are monitored closely by California Native Plant Society volunteers; by 1994, they had not observed any of these plants set seed for several years. Much of the habitat for L. pardalinum ssp. pitkinense has been invaded by blackberry vines that compete for space, light, and nutrients.

The historical range of L. pardalinum ssp. pitkinense also occurs within the project boundaries of a wastewater treatment plant, which in the late 1990s was operating without discharging recycled waste-water onto surrounding sensitive habitat. Should the plant do so, as was originally planned before construction commenced, the hydrology of the habitat drenched with wastewater could be adversely affected, with probably harmful consequences to this taxon.

Conservation and Recovery

The landowners of the two confirmed populations of L. pardalinum ssp. pitkinense entered into voluntary protection agreements with the Nature Conservancy (TNC) in 1989. Since then, TNC and the California Conservation Corps have jointly built and maintained cattle exclosures in an attempt to protect the plants at both sites. Some plants, however, continue to suffer herbivory from livestock and wildlife, resulting in loss of flowers and seeds. A memorandum of understanding is currently in effect between the CDFG and the Berry Botanic Garden in Portland, Oregon, for research on germination and recovery of this species.

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/

Reference

U. S. Fish and Wildlife Service. 22 October 1997. "Determination of Endangered Status for Nine Plants from the Grasslands or Mesic Areas of the Central Coast of California." Federal Register 62 (204): 54791-54808.