Section II: Species Information - Coptis asplenifolia

VII. Coptis aspleniifolia Salisb. (Spleenwort-leaved Goldthread)

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

A. Introduction

Coptis aspleniifolia is an evergreen perennial rhizomatous herb with shiny, fern-like basal leaves in the Ranunculaceae (buttercup family). Spleenwort-leaved goldthread is the common name most often applied to this species.

Coptis aspleniifolia occurs in cool, moist, old-growth forest habitats in Washington, where it is restricted to localized populations in the western North Cascades and western Olympics. It 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). Coptis aspleniifolia is listed on the Region 6 Regional Forester's Sensitive Species List; it is a Bureau of Land Management Assessment Species in Washington State, and a Washington Natural Heritage Program Sensitive Species (Lesher and Henderson 1998).

B. Unique Characteristics, Biology, and Ecology

Coptis aspleniifolia is an evergreen perennial herb with shiny, fern-like basal leaves. The bright yellow thread-like rhizomes led to the origin of the common name "goldthread" (Pojar and MacKinnon 1994). Its rhizomatous habit creates extensive spreading mats. It is a compact, low growing plant from 10-30 cm (3.9-11.8 inches) tall. Leaves are divided into 5 or more lobed and toothed leaflets that are 2-6 cm (0.8-2.4 inches) long.

This species is similar in morphology to Coptis laciniata, which is more common and widespread in the western Olympics and extends south into northwestern California. It differs primarily in the number of leaflets and height of the flowering stalk relative to the leaves. Coptis aspleniifolia has at least 5 leaflets and the flowering stalk is taller than the leaves at anthesis; Coptis laciniata has 3 leaflets, and the flowering stalk is shorter than the leaves. All goldthreads have a touch of yellow at the base of the leaf stalk.

Flowers are inconspicuous, greenish-white and regular, with 2-3 flowers nodding on a leafless stalk. The flowering stalk is usually taller than the leaves at anthesis, and has hyaline scales at the base. Sepals are somewhat linear and reflexed, 5-6 in number, 6-15 mm (2.4-5.9 inches) long. Petals are the same in number as the sepals, but shorter and strap-shaped with a broader, glandular base. Stamens are numerous. It flowers early in the season, from late April through May.

Fruits are follicles, up to 12 in a head, 7-9 mm (2.8-3.5 inches) long, membranous with a very short beak, and with 5-10 seeds. Fruits are upright and spreading when mature. The fruits split open along the upper side, which is believed to be an adaptation for splash-cup dispersal (Pojar and MacKinnon 1994). Fruits are visible beginning in May or June.

Coptis aspleniifolia reproduces both vegetatively and sexually. Germination and seedling emergence was completed by September following a winter on the forest floor. Establishment of Coptis aspleniifolia may be limited by the low light levels in moss mats, as the seedlings are only 10-12 mm (3.9-4.7 inches) tall compared with the moss height of 15-20 mm (5.9-7.9 inches) . Average annual rhizome growth is 1-15 cm (0.4-5.9 inches) in older stands. C. aspleniifolia maintains itself in old stands by both seedling establishment and vegetative development of clones. However, the compact clones of this species may limit its ability to migrate by vegetative growth compared to other species (Tappeiner and Alaback 1989).

C. Specific Habitat Associations

Coptis aspleniifolia occurs in moist forests and bogs (Hitchcock et al. 1964), at low to middle elevations, in areas with a strong maritime influence (Klinka et al. 1989). It is common and widespread in Alaska and British Columbia (Pojar and MacKinnon 1994), but becomes restricted to localized populations in the western North Cascades and western Olympics. At the southern limit of its range, it occurs in cool, moist, old-growth forest habitats.

In coastal British Columbia, Coptis aspleniifolia indicates very moist, acidic, nitrogen poor soils with high organic matter content and generally occurs on forest floors matted by fungal mycelia (Klinka et al. 1989). It is commonly associated with Sphagnum girgensohnii and Blechnum spicant.

Habitat information is limited for Coptis aspleniifolia in northwestern Washington or the Oregon Coast Range. On the Mt. Baker-Snoqualmie National Forest, it occupies cool, moist sites that are similar climatically to environments farther north in British Columbia and Alaska. It occurs adjacent to wetlands, rivers, streams or lakes, or on higher ground in areas with high precipitation, and generally in sites with low evaporative stress. Sites are generally on gentle lower slopes, and often northerly aspects. It is thought that these sites have low incident solar radiation because of their location on the landscape. Sites have a mean annual temperature less than 9C (48F), and average annual precipitation greater than 250 cm (100 inches) (Henderson 1995).

Known populations from the Mt. Baker-Snoqualmie National Forest occur in old-growth to near climax forests, with canopy structure ranging from closed to open and patchy. Coptis aspleniifolia occurs in moist plant associations in the Western Hemlock Zone or lower Silver Fir Zone. Overstory tree species are commonly western hemlock, western redcedar and occasionally Pacific silver fir. Common associated understory species include Sphagnum spp., Blechnum spicant, Rubus pedatus, Lysichitum americanum, Maianthemum dilatatum, Cornus canadensis, Tiarella unifoliata, Athyrium filix-femina, Oplopanax horridum, Vaccinium alaskaense, Rubus spectabilis, Gymnocarpium dryopteris, Galium kamtschaticum, Ribes bracteosum, Listera cordata, Menziesia ferruginea and Cladothamnus pyrolaeformis. Sites where Coptis aspleniifolia occurs often have a well-developed moss or duff layer, or wet organic soil.

On the Olympic Peninsula, both populations occur in areas with high precipitation, >250 cm (100 inches) and high humidity (Henderson 1995). The Bogachiel population occurs at 670 m (2200 ft.) elevation in a boggy site along the trail. This site was originally reported in 1967 and was revisited in 1994. The Harlow Creek site occurs on DNR land in a designated Forest Health Plot. This stand was harvested about 15 years ago but not burned, and currently has about 20 percent cover of western hemlock. Understory species on this wet site include abundant Sphagnum, Gaultheria shallon, Vaccinium ovalifolium, Carex obnupta, Menziesia ferruginea, and Blechnum spicant. This population of Coptis aspleniifolia was reported as very large.

D. Range of Coptis aspleniifolia

1. Known Range

Coptis aspleniifolia occurs from south central Alaska, south through coastal British Columbia to Washington, and perhaps Oregon (Hitchcock et al. 1964; Hitchcock and Cronquist 1973; Pojar and MacKinnon 1994; Hulten 1968; Buckingham and Tisch 1979; USDA Forest Service and USDI Bureau of Land Management 1994b; Lesher and Henderson 1998). In the Washington Cascades, this species is known from 3 populations in Snohomish County, the Skykomish River basin at Lake Isabel and the Wallace River, and Lake Twenty-two Research Natural Area in the South Fork of the Stillaguamish River basin (Lesher and Henderson 1998).

Four populations of Coptis aspleniifolia have been reported from the westside of the Olympic Peninsula, although currently only 2 sites are known to exist. Two Olympic Peninsula populations were verified in 1994 in Clallam and Grays Harbor Counties. The known population on federal land occurs in Olympic National Park on the Bogachiel River. The other population reported in 1994 occurs on Washington State Department of Natural Resources land in the Harlow Creek area of the southwestern Olympic Peninsula. The other 2 populations previously documented in Jefferson County were searched for in 1994 but not relocated. These populations occurred on the Quinault Indian Reservation and Washington State Department of Transportation land (Lesher and Henderson 1998).

2. Suspected Range

Coptis aspleniifolia has been reported from the Oregon Coast Range (USDA Forest Service and USDI Bureau of Land Management 1994b), but a search of the Oregon State University Herbarium revealed only one specimen originally identified as Coptis aspleniifolia from Tillamook County on Roger's Peak within the Tillamook Burn area (Lesher and Henderson 1998). This specimen has since been annotated as Coptis laciniata by Dr. Kenton Chambers. Therefore, Coptis aspleniifolia is not suspected outside of northwest Washington.

E. Timing of Surveys

Coptis aspleniifolia flowers early in the season, from late April through May. Surveys should be conducted during the growing season, generally June through September. However, in the Olympics where ranges of Coptis aspleniifolia and Coptis laciniata overlap, the surveys should occur when the plants are in flower or fruit, generally late April through June.

F. Threats

Management Recommendations (Lesher and Henderson 1998) identified the major threats to C. aspleniifolia as follows:

Any actions that alter the moisture or temperature regime, or actions that cause disturbance to the soil litter layer.

Trampling from recreational use

Deer browsing is a potential threat to this species in Washington

REFERENCES

Buckingham, N. M. and E. L. Tisch. 1979. Vascular Plants of the Olympic Peninsula, Washington. National Park Service and Cooperative Park Studies Unit, College of Forest Resources, University of Washington. UW/CPSU Report B-79-2.

Henderson, J. A. 1995. Unpublished Potential Natural Vegetation Model, Mt. Baker-Snoqualmie National Forest and Olympic National Forest.

Hitchcock, C. L. and A. Cronquist. 1973. Flora of the Pacific Northwest. University of Washington Press, Seattle. 730 p.

Hitchcock, C. L., A. Cronquist, M. Ownbey and J. W. Thompson. 1964. Vascular Plants of the Pacific Northwest. Part 2: Salicaceae to Saxifragaceae. University of Washington Press, Seattle. 597 p.

Hulten, E. 1968. Flora of Alaska and Neighboring Territories. A Manual of the Vascular Plants. Stanford University Press. Stanford, CA. 1008 p.

Klinka, K., V. J. Krajina, A. Ceska and A. M. Scagel. 1989. Indicators Plants of Coastal British Columbia. University of British Columbia Press. Vancouver. 288 p.

Lesher, R. D., and J. A. Henderson. 1998. Management Recommendations for Spleenwort-leaved Goldthread (Coptis aspleniifolia Salisb.). Unpublished manuscript.

Pojar, J. and A. MacKinnon (eds). 1994. Plants of the Pacific Northwest Coast. B.C. Ministry of Forests and Lone Pine Publishing. Canada. 527 p.

Tappeiner, J. C. II, and P. B. Alaback. 1989. Early establishment and vegetative growth of understory species in the western hemlock-Sitka spruce forests of southeast Alaska. Can. J. Bot. 67: 318-326.

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.