XV. Scoliopus bigelovii Torrey (Bigelow's adder's tongue)

Area of Application: Throughout the area covered by the Northwest Forest Plan.

A. Introduction

Scoliopus bigelovii is a long-lived perennial herb in the Liliaceae (lily) plant family. Common names applied to this species include Bigelow's adder's tongue, fetid adder's tongue, and slink pod.

Scoliopus bigelovii is considered to be associated with old-growth habitat, and is classified as a Survey and Manage Strategy 1 and 2 species under the FSEIS/ROD (USDA Forest Service and USDI Bureau of Land Management 1994a, 1994b). It is considered too common to be classified as rare, threatened, or sensitive in California (Skinner and Pavlik 1994; California Natural Diversity Data Base 1994), and is not on the USFS Region 5 Regional Foresters Sensitive Species List (Williams 1996).

B. Unique Characteristics, Biology, and Ecology

The following is a technical description of Scoliopus bigelovii:

Leaves elliptic to oblong, 1-2 dm long, 0.5-1 dm wide, obtuse to acute, sheathing at base. Pedicels 3-12, 1-2 dm long, three-angled, erect at anthesis, tortuous-recurved in fruit. Sepals lanceolate-ovate, 14-17 mm long, greenish, with reddish veins. Petals about equal to the sepals. Stamens 5-6 mm long. Stigmas 5-6 mm long, spreading-recurved. Fruit a capsule, 15-18 mm long. Seeds about 3 mm long (from Munz 1959).

Scoliopus bigelovii exhibits specialized pollination by fungal gnats belonging to closely related families Mycentophilidae (Mycetophilla sp.) and Sciarideae (Sciara sp., Corynoptera sp.) (Messler et al. 1980). It is self-incompatible (Berg 1959; Messler et al. 1980). Subterranean stems, elongated twisting pedicels, capsules dehiscing in the upper duff layers, and elasiosomes fascilitate seed dispersal by ants (Formica fusca, F. rufibaris, Aphaenogaster subterranea) (Utech 1992; Berg 1959). Slugs may play a role in seed dispersal by eating pod walls (USDA Forest Service and USDI Bureau of Land Management 1994b). Scoliopus bigelovii may bloom as early as December 15 (USDA Forest Service and USDI Bureau of Land Management 1994b), with the time of seed ripening coincident with the time of year when ants are most active (Berg 1959).

C. Specific Habitat Associations

Scoliopus bigelovii inhabits moist, shaded slopes below 2500 feet. It occurs primarily on shady mesic understory slopes of old-growth coastal Californian redwood forests (USDA Forest Service and USDI Bureau of Land Management 1994b), but also occurs in coastal Douglas-fir and mixed evergreen forests (Williams 1996). Scoliopus bigelovii is often found in ephemeral springs or seepage areas, but is also documented from drier, more open habitats such as rocky outcroppings on coastal headlands and cobbly bluffs. The factor that is likely to be limiting to its distribution is temperature as it is restricted to the coastal fog belt (USDA Forest Service and USDI Bureau of Land Management 1994b). This species does not favor recently disturbed sites and may require habitats without heavy competition from other herbaceous and shrub species (Williams 1996). Common understory associates include Polystichum munitum, Clintonia andrewsiana, Trillium ovatum, Dentaria integrifolia, Oxalis oregana, Viola sempervirens, and Trientalis latifolia.

D. Range of Scoliopus bigelovii

1. Known Range

Scoliopus bigelovii is found within the range of coastal redwood forests in California from the Santa Cruz Mountains in Monterey County, north to the Oregon border. Within the range of the northern spotted owl most redwood habitat is on nonfederal land (USDA Forest Service and USDI Bureau of Land Management 1994b). The species is reported to be widespread but scattered and locally common on some private lands and coastal State parks (Williams 1996). It occurs on BLM land (USDA Forest Service and USDI Bureau of Land Management 1994b) and is common in Redwood National Park (Williams 1996). Abundance is unknown on the Six Rivers National Forest, but it is reported as uncommon within the Yurok Research Natural Area (Taylor 1982). There is no known habitat on the Siskiyou National Forest (Kagan 1987; Williams 1996).

2. Suspected Range

Although most sources report Scoliopus bigelovii as being endemic to California (Hickman 1993; Munz 1959; Abrams 1923; Hitchcock et al. 1969), 1 or 2 populations have been reported in redwood old-growth fragments in Oregon near the California border within 6 miles of the coast (USDA Forest Service and USDI Bureau of Land Management 1994b).

E. Timing of Surveys

Scoliopus bigelovii may bloom as early as December 15, but peak flowering is in February and March (Munz 1959). Surveys should be conducted during the flowering period when plants are most easily seen and identifiable.

F. Threats

The major threats to S. bigelovii can be summarized as follows (Williams 1996):

• clearcutting can have short term (10-40 years) negative effects
• dense populations of deer may limit reproductive success
• fire suppression
• urbanization
• nontarget effects of herbicides

REFERENCES

Abrams, L. R. 1923-1960. An Illustrated Flora of the Pacific States, Washington, Oregon and California. Stanford University Press. Stanford, CA.

Berg, R. Y. 1959. Seed dispersal, morphology, and taxonomic position of Scoliopus, Liliaceae. Skrifter Utgitt av Det Norske Videnskaps-Akademi Oslo 1. Mat.-Naturv. Klasse 4: 1-56

California Natural Diversity Data Base, RAREFIND. 1994.

Hickman, J. C. (Ed.). 1993. The Jepson Manual: Higher Plants of California. University of California Press. Berkeley, CA.

Hitchcock, C. L., A. Cronquist, M. Owenby, J. W. Thompson. 1969. Vascular Plants of the Pacific Northwest. University of Washington Press. Seattle, WA.

Kagan, J. 1987. Draft Species Management Guide for Clintonia andrewsiana. Submitted to the Siskiyou National Forest Nov. 30, 1989. Oregon Natural Heritage Program, Portland, OR.

Messler, M. R., J. D. Ackerman, and. K. L. Lu. 1980. The effectiveness of fungal gnats as pollinators. Amer. J. Bot. 67: 564-567.

Munz, P. A. 1959. A California Flora and Supplement. In collaboration with D. D. Keck. University of California Press. Berkeley, CA.

Skinner, M. W., and B. M. Pavlik. 1994. California Native Plant Society's Inventory of Rare and Endangered Vascular Plants of California. The California Native Plant Society. Sacramento, CA.

Taylor, D. W. 1982. Ecological Survey of the Vegetation of the Yurok Research Natural Area, California. A report to U.S. Forest Service Pacific Southwest Forest & Range Experiment Station. Contract 40-9AD6-2-793.

USDA Forest Service and USDI Bureau of Land Management. 1994a. Final supplemental environmental impact statement on managing of habitat for late successional and old-growth species within the range of the northern spotted owl. Portland, Oregon.

USDA Forest Service and USDI Bureau of Land Management. 1994b. Final supplemental environmental impact statement on managing of habitat for late successional and old-growth species within the range of the northern spotted owl. Appendix J2, Results of Additional Species Analysis. Portland, Oregon.

Utech, F. H. 1992. Biology of Scoliopus (Liliaceae) I. Pytogeography and Systematics. Ann. Missouri Bot. Gard. 79: 126-142.

Williams, Barbara. 1996. Interim Management Guidelines for Survey and Manage Listing Change, Scoliopus bigelovii (Slink Pod). Unpublished manuscript.