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Conserving and restoring
America's native plants |
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CPC National Collection Plant Profile
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Calochortus coxii
| Family: |
Liliaceae (Lily Family) |
| Common Names: |
Cox's mariposa-lily, crinite mariposa lily |
| Author: |
Godfrey & Callahan |
| Growth
Habit: |
Perennial |
| CPC
Number: |
9791 |
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| Primary
custodian for this plant in the CPC National Collection of Endangered
Plants is: |
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| Edward Guerrant, Ph.D. contributed to this Plant Profile. |
Calochortus coxii
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When the crinite mariposa lily is not in bloom, it can be difficult to distinguish from grasses and is easily overlooked. Perhaps for this reason it was not discovered until the spring of 1988. However, this plant is akin to the ugly ducking that matures into a swan, as reproductive plants are graced with attractive, white, cup-shaped flowers each spring.
The Calochortus genus contains a relatively large number of rare, localized, and endemic taxa (Feidler et at. 1998). The crinite mariposa lily is one such taxon. It occurs only within a narrow 30-mile (50-km) long band of serpentine soil that contains large amounts of iron and magnesium (Fredricks 1992). Even within this specific soil type, the crinite mariposa lily is not widely distributed as it primarily occupies the transition zone between coniferous forests and meadows.
| Distribution
& Occurrence |
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State Range
Habitat
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• Restricted to serpentine soils (Knight and Seevers 1992). Primarily found in the transition zone (ecotone) between coniferous forests and grass-shrub meadows, but also found in meadows (Fredricks 1993).
• Elevation 1400 to 2500 ft. (420-760 m) (Fredricks 1989). |
Distribution
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Klamath Mountains of Oregon. |
Number Left
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There are 11 known sites, of which 8 are on Bureau of Land Management (BLM) land and 3 on private land. Population numbers as of 1992 and 1993 ranged from as little as two individuals to over 5,000, but most populations contained between 100 and 1000 individuals (ONHDB 2000). |
State/Area
Protection
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State/Area |
Rank |
Status |
Date |
|
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Oregon |
S1 |
LE |
7/12/1995 |
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| Conservation,
Ecology & Research |
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Ecological
Relationships
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Calochortus coxii is restricted to serpentine-derived soils, but despite the widespread occurrence of these soils, a considerable amount of apparently suitable habitat is unoccupied (Fredricks 1989 in Fredricks 1993). Within this restricted geography (due to the soil preferences), it has a limited distribution, and is most frequently found in the narrow transition zone (ecotone) between mixed coniferous forests and grass-forb meadows. Sites inhabited by C. coxii are typically intact, relatively undisturbed plant communities (Fredricks 1993).
Physical and chemical properties of serpentine soils that may cause reduced reproductive success include restricted rooting depth, stoniness, low levels of molybdenum, paucity of soil micro-organisms, low levels of available macronutrients, high levels of nickel, chromium, zinc, and magnesium and low calcium to magnesium ratio (Rai et al. 1970 in Fredricks 1992).
Most research shows that in cultivation, serpentine endemics grow robustly on non-serpentine soil. Competition and the presence of pathogenic fungi not found on serpentine are most commonly suggested as the factors limiting plants to serpentine soils (Fredricks 1993). Fielder (1985) hypothesizes that heavy metal tolerance in Calochortus may be an exadaptation, meaning that it evolved early but has been repeatedly lost throughout the lineage.
Growth rates of Calochortus coxii appear slower than those of Calochortus umpquaensis, especially when compared across the same habitat. C. coxii most commonly occupies litter and moss habitats, with the litter microsites the most common and comprising the greatest cover. While bud production is higher in C. coxii than in the forest and meadow habitats of C. umpquaensis, capsule production and recruitment are significantly lower. Grazing and seed predation may contribute to this low fecundity (Fredricks 1993). Grazing of vegetative matter causes a reduction in size and reproduction the following year due to depletion of carbohydrate reserves (Fredricks 1989). The high variability in seed set may also indicate that pollination may be limited. Unlike other species of Calochortus, which are frequently visited by beetles and bees, insect visitors to C. coxii are rarely observed. The sparseness of flowering individuals may also be responsible for low pollination (Fredricks 1993).
Calochortus coxii reproductive output varies considerably across habitat. In general, Calochortus life history is typical of long-lived herbaceous perennials: individual survival makes the largest contribution to growth rate, reproduction and mortality appear episodic, and reproductive success and seedling establishment appear to limit populations to certain habitats (Feidler et al. 1998). |
Threats
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• Bulb collection and flower picking (Fredricks 1989).
• Grazing (Fredricks 1993).
• Seed predation (Fredricks 1993). |
Current Research Summary
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• In a three-year comparative demographic study of Calochortus coxii, permanent plots were monitored at two sites. Among C. coxii plants, bud production was highest and plants were most dense and larger on average in the ecotone (transition between coniferous forest and forb/grass meadow) habitat. Transition matrix models revealed that C. coxii was stable at one site, but clearly declining at another. Results were compared to a similar study with Calochortus umpquaensis (Fredricks 1993).
• Demographic comparisons using matrix model analysis of empirical data were made among eight Calochortus species. Results paint a mixed picture of population dynamics. For all species, population stage distribution (proportion of seedlings, juveniles, and reproductive adults) was highly variable between populations, habitats, and years. (Feidler et al. 1998).
• Germination trials indicate that germination is stimulated by long periods (12-14 weeks) of cold, moist, dark stratification. This ensures that the seed will only germinate in the spring, when the seedlings chance for survival is greatest (Florance 1994).
• In germination studies at The Berry Botanic Garden, 100% germination was obtained after 8 weeks of cold stratification followed by a constant 68°F (20°C) environment. Between 80-100% of seeds germinated with 8 weeks of cold stratification and an alternating 50°F/68°F (10/20°C) environment (BBG file). |
Current Management Summary
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• Seeds from three locations stored at The Berry Botanic Garden. |
Research Management Needs
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• Survey potential habitat for additional populations (Fredricks 1989).
• Determine the mechanism facilitating endemism to serpentine soils (Fredricks 1989).
• Soil and microsite analysis to identify critical factors to recruitment and success (Fredricks 1989).
• Continued monitoring (Fredricks 1992). |
Ex Situ Needs
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• Collect and store seeds from known populations.
• Determine optimum propagation procedures and develop reintroduction protocols. |
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| Books (Single Authors)
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| ONHP. 2001. Rare, Threatened and Endangered Plants and Animals of Oregon. Portland, Oregon: Oregon Natural Heritage Program. 94p. |
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| Books (Sections)
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| Fiedler, P.L.; Knapp, B.; Fredericks, N. 1998. Rare plant demography: Lessons from the Mariposa Lilies (Calochortus: Liliaceae). In: Fiedler, P.L.; Kareiva, P. M., editors. Conservation Biology: Conservation for the Coming Decade. Chapman & Hall. New York. p 28-48. |
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| Kartesz, J.T. 1999. A synonymized checklist of the vascular flora of the U.S., Canada, and Greenland. In: Kartesz, J.T.; Meacham, C.A., editors. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden. Chapel Hill, NC. |
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| Electronic Sources
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| ONHDB. (2000). Oregon Natural Heritage Program Database. Portland, Oregon. |
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| Journal Articles
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| Fiedler, P.L. 1985. Heavy metal accumulation and the nature of edaphic endemism in the genus Calochortus (Liliaceae). American Journal of Botany. 72: 1712-1718. |
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| Fiedler, P.L. 1986. Concepts of rarity in vascular plant species, with special reference to the genus Calochortus Pursh (Liliaceae). Taxon. 35: 502-518. |
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| Fiedler, P.L. 1987. Life history and population dynamics of rare and common mariposa lilies (Calochortus: Liliaceae). Journal of Ecology. 75: 977-995. |
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| Godfrey, M.R.; Callahan, F.T., II. 1988. A new Calochortus from Douglas County, Oregon. Phytologia. 65, 3: 216-219. |
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| Reports
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| BLM. 1999. Calochortus coxii Habitat Restoration. Environmental Assessment. Decision Record. Bureau of Land Management, South River Field Office. p.2. EA# OR - 105 - 99 - 09. |
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| BLM. 1999. Calochortus coxii Habitat Restoration. Environmental Assessment. Finding of No Significant Impact. Bureau of Land Management, South River Field Office. p.2. EA# OR - 105 - 99 - 09. |
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| Florance, E.R. 1994. Germination, Dormancy, and Structure of Seeds From Rare and Endangered Plant Species in Oregon. Unpublished Final Report. Cooperative Challenge Cost-Share Project funded by Bureau of Land Management and Lewis and Clark College. |
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| Fredricks, N. 1989. Calochortus coxii: Preliminary Status Report and Summary of 1989 Field Studies. Unpublished Report prepared for the Oregon Department of Agriculture for Submission to the Roseburg District B.L.M. |
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| Knight, L.; Seevers, J. 1992. Special Status Plants of the Medford District BLM. Medford, Oregon: Bureau of Land Management-Medford District. p.228. |
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| Rai, D.; Simonsen, G.H.; Youngberg, C.T. 1970. Serpentine derived soils in watershed and forest management. Report for the USDI Bureau of Land Management, Department of Soils. Oregon State University, Corvalis. |
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| Theses
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| Fredricks, N.A. 1993. Population biology of rare mariposa lilies (Calochortus: Liliaceae) endemic to serpentine soils in southwestern Oregon. [Ph.D. Thesis]: Oregon State University. Corvallis, Oregon. |
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