BC Conservation Data Centre: Species Summary
Microseris bigelovii
coast microseris
| Scientific Name: | Microseris bigelovii (Gray) Schultz-Bip. | ||||||||||
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| English Name: | coast microseris | ||||||||||
| Classification / Taxonomy | |||||||||||
| Scientific Name - Concept Reference: | Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR. | ||||||||||
| Classification Level: | Species | ||||||||||
| Species Group: | Vascular Plant | ||||||||||
| Species Code: | MICRBIG | ||||||||||
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| Conservation Status / Legal Designation | |||||||||||
| Global Status: | G4 (Apr 1995) | ||||||||||
| Provincial Status: | S2 (Apr 2019) | ||||||||||
| BC List: | Red | ||||||||||
| Provincial FRPA list: | |||||||||||
| Provincial Wildlife Act: | |||||||||||
| COSEWIC Status: | Endangered (Apr 2006) | ||||||||||
| SARA Schedule: | 1 - Endangered (Dec 2007) | ||||||||||
| General Status Canada: | 1 - At Risk (2010) | ||||||||||
| Ecology & Life History | |||||||||||
| General Description: | |||||||||||
| Technical Description: | |||||||||||
| Subspecies Comments: | No subspecies of Microseris bigelovii are recognized in B.C. | ||||||||||
| Identification Comments: | Microseris bigelovii is a taprooted annual with erect to ascending or decumbent leafless stems. Plants are 4-35 cm tall. Basal leaves are 3-25 cm long, linear to oblanceolate or spoon-shaped, entire or coarsely pinnately cut with slender or broad tapering lobes or teeth. Foliage exudes a milky juice when broken. Plants have solitary and terminal heads of yellow to yellow-orange strap-shaped flowers which are nodding until mature. Flowers are enclosed in a 6-15 mm tall involucre of broadly lanceolate bracts, often reddish on the outside and blackish hairy inside. Fruits are brown to bronze (sometimes darkly-spotted) achenes. Achenes are 2.5-6 mm long, abruptly tapered at the base, and crowned by a pappus of five glabrous or short-hairy lanceolate scales, each terminating in a long, hair-like bristle arising from the pointed scale (Douglas et al. 1998b; COSEWIC 2006b). | ||||||||||
| Similar Species: | There are three species of Microseris in B.C. that could be confused with Microseris bigelovii: M. borealis, M. nutans, and M. lindleyi. M. borealis and M. nutans are perennials which have more conspicuous ray flowers that well exceed the involucre. M. lindleyi and M. bigelovii are annuals which have inconspicuous ray flowers that equal or barely exceed the involucre. Only M. lindleyi has a similar distribution to M. bigelovii. M. bigelovii has lanceolate pappus scales, each terminating in a long, hair-like bristle arising from a pointed scale, and has leafless, unbranched stems. M. lindleyi has linear pappus scales, each terminating in a short hair-like bristle arising from a distinctly-notched scale, and has stems that are leafy below and branched at or near the base (Douglas et al. 1998b; COSEWIC 2006b). | ||||||||||
| Provincial Reproduction Comments: | Asexual reproduction does not occur in Microseris bigelovii. Because it is an annual plant, it depends on successful sexual reproduction for its persistence. Flowering is asynchronous and flowers are short-lived. Pollinators are not known. The number of populations and subpopulations, defined by rate of gene exchange via seed movement and pollen exchange, is difficult to establish (COSEWIC 2006b). Seed dispersal between patches is probably restricted to fairly short distances. Self-pollination is known to occur frequently, but it is not clear how often pollen is exchanged or over what distances it occurs (COSEWIC 2006b). Occasional low-level outcrossing does occur (K. Chambers, pers. comm., in COSEWIC 2006b). Genetic variation within and among populations has not been studied, but populations of M. bigelovii in BC are considered to be genetically distinct from Californian populations (Van Heusden and Bachman 1992 in COSEWIC 2006b). | ||||||||||
| Provincial Ecology Comments: | There is very little published information on the biology or ecology of Microseris bigelovii. Specific factors affecting population survival, population age structure, recruitment rate, seedling survival rates, mortality rates, and growth rates are not known. Preliminary studies on the biology of M. bigelovii in B.C. were conducted by M. Fairbarns for the preparation of a COSEWIC status report (COSEWIC 2006b). The species germinates in autumn or late winter/early spring, and likely depends on having suitable soil moisture in the autumn. COSEWIC (2006b) hypothesized that plants growing with Cladina portentosa tend to germinate in autumn. The lichens absorb moisture during nocturnal fogs and retain it throughout the next day, thereby providing moisture for germination of M. bigelovii (COSEWIC 2006b). Seedlings grow quickly before winter and persist until warmer weather occurs in the spring. Plants that do not grow with C. portentosa do not germinate until late winter or spring. Seeds do not exhibit dormancy, and 90% germinated when watered in a small germination experiment (COSEWIC 2006b). Seeds are likely dispersed short distances by gravity or wind, but there is some evidence for dispersal by birds (COSEWIC 2006b). No herbivory, pests, or diseases have been observed in the B.C. populations of this species. | ||||||||||
| Habitats: (Type / Subtype / Dependence) |
Grassland/Shrub / Meadow / Facultative - frequent use
Other Unique Habitats / Vernal Pools/Seasonal Seeps / Facultative - frequent use Rock/Sparsely Vegetated Rock / Garry Oak Coastal Bluffs / Facultative - frequent use Rock/Sparsely Vegetated Rock / Rock/Sparsely Vegetated Rock / Facultative - frequent use |
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| Provincial Habitat Comments: | Microseris bigelovii occurs in low lying, level to near-level open meadows and sparsely vegetated gravel sites that experience winter seepage and summer desiccation (COSEWIC 2006b). The species is restricted to coastal areas (i.e., it occurs within 50 m of the coast) where the mesoclimate is ameliorated by oceanic influences (low variation in temperatures and few deep frosts). Sites are exposed to frequent occurrences of fog in autumn and winter, winds, and erosion from seepage. M. bigelovii's habitat is closely associated with Garry oak ecosystems, which are part of the drier subzone of the Coastal Douglas-fir zone (CDFmm) (Douglas et al. 2002). The Garry oak ecosystem is very restricted in southwestern B.C. and has been reduced to less than 5% of its original extent (Fuchs 2001). The climate of the CDFmm is Mediterranean-like and characterized by mild, wet winters and warm, dry summers. M. bigelovii tolerates dry sandy soils and may require frequent occurrences of coastal fog. It also tolerates high levels of nitrogen/fertility when growing near bird guano (COSEWIC 2006b). Its ability to tolerate adverse conditions may explain its frequent occurrence in sparsely vegetated areas. Populations occur on rock ledge sites and on the margins of shallow depressions that are wet in winter. Associated species on rock ledge sites are Cladina portentosa, Selaginella wallacei, Gnaphalium purpureum, Grindelia integrifolia, Hypochaeris radicata, H. glabra, Lotus micranthus, and Rumex acetosella (Fairbarns et al. 2004b). Common plants of shallow depressions are Aphanes microcarpa, Cerastium arvense, G. purpureum, H. glabra, H. radicata, Plagiobothyrus scouleri, Plantago elongata, and Trifolium spp. (COSEWIC 2006b). | ||||||||||
| Provincial Phenology: (1st half of month/ 2nd half of month) |
Jan: Vegetative, Germinating / Vegetative, Germinating
Feb: Vegetative, Germinating / Vegetative, Germinating Mar: Vegetative, Germinating / Vegetative, Germinating Apr: Vegetative / Vegetative May: Vegetative, Flowering / Vegetative, Flowering Jun: Vegetative, Flowering, Fruiting / Vegetative, Flowering, Fruiting Oct: Germinating / Germinating Nov: Vegetative, Germinating / Vegetative, Germinating Dec: Vegetative, Germinating / Vegetative, Germinating |
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| Provincial Phenology Comments: | The phenology of Microseris bigelovii depends on weather conditions. If soils becomes suitably moist, seeds can germinate in autumn, and seedlings can grow quickly before the onset of cold winter temperatures and persist through winter until warmer weather occurs in spring (COSEWIC 2006b). Plants that do not experience suitable moisture conditions germinate in late winter or spring; therefore, germination in B.C. can extend from October to March. Plants flower in May or June, produce seeds in June, and die before the droughty summer months of July, August, and September. | ||||||||||
| Elevation (m) (min / max): | Provincial: 7 / 25 | ||||||||||
| Known Pests: | |||||||||||
| Pollen Vector: | |||||||||||
| Pollinator: | |||||||||||
| Dispersal: | |||||||||||
| Provincial Inventory | |||||||||||
| Inventory Priority: | D - Low | ||||||||||
| Ownership of occurrences (Known locations): | Mixed government | ||||||||||
| Inventory Need: | There is low priority for further inventories of Microseris bigelovii in B.C. New populations may be encountered along shorelines of under-collected or infrequently visited Gulf Islands. Rock ledges on rugged shorelines that are difficult to access may also support new populations. COSEWIC (2006b) did not make specific recommendations for future inventories. | ||||||||||
| Inventory Comments: | Since the early 1980s, inventories of Microseris bigelovii have been done by expert botanists who are familiar with the species and its preferred habitat. Over 1000 ha of suitable habitat in more than 80 sites have been searched, some repeatedly, since the early 1980s (COSEWIC 2006b). COSEWIC (2006b) did three additional searches in 2002, 2003, and 2004, totalling 28 person-days, during the preparation of a COSEWIC status report. No additional populations were discovered, though it is still possible but unlikely that new populations will be discovered in the future. | ||||||||||
| Economic Attributes | |||||||||||
| Provincial Economic Comments: | There are no known economic uses for Microseris bigelovii. | ||||||||||
| Distribution | |||||||||||
| Endemic: | N | ||||||||||
| Disjunct, more common elsewhere: | Y | ||||||||||
| Peripheral, major distribution elsewhere: | Y | ||||||||||
| Authors / Contributors | |||||||||||
| Global Information Author: | |||||||||||
| Last Updated: | |||||||||||
| Provincial Information Author: | Bartemucci, P. | ||||||||||
| Last Updated: | Jan 23, 2008 | ||||||||||
| Last Literature Search: | |||||||||||
| References and Related Literature | |||||||||||
B.C. Ministry of Environment. Recovery Planning in BC. B.C. Minist. Environ. Victoria, BC. |
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COSEWIC. 2006b. COSEWIC assessment and status report on the coast microseris Microseris bigelovii in Canada. Comm. on the Status of Endangered Wildl. in Can. Ottawa. vi + 26 pp. |
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Douglas, G.W., D. Meidinger, and J. Penny. 2002. Rare Native Vascular Plants of British Columbia, 2nd ed. B.C. Conserv. Data Centre, Terrestrial Inf. Branch, Victoria. 358pp. |
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Douglas, G.W., G.D. Straley, and D. Meidinger, eds. 1998b. Illustrated Flora of British Columbia, Vol. 1, Gymnosperms and Dicotyledons (Aceraceae through Asteraceae). B.C. Minist. Environ., Lands and Parks, Wildl. Branch, and B.C. Minist. For. Res. Program. 436pp. |
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Fairbarns, M., A. MacDougall, A. Ceska and O. Ceska. 2004. COSEWIC status report on Coastal Silverpuffs, Microseris bigelovii, prepared for Comm. on the Status of Endangered Wildl. in Can. Funding provided by the Garry Oak Ecosystem Recovery Team and the BC Conservation Data Centre. 20 pp. |
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Fuchs, Marilyn A. 2001. Towards a Recovery Strategy for Garry Oak and Associated Ecosystems in Canada: Ecological Assessment and Literature Review. Tech. Rep. GBEI/EC-00-030. Environ. Can., Can. Wildl. Serv., Pac. and Yukon Region. |
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Harper, J. L. 1977. Population biology of plants. Academic Press, New York, NY. |
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MacDougall, A. 2002. Stewardship Account for Coastal Microseris, Microseris bigelovii. Prepared for the B.C. Conservation Data Centre and the Garry Oak Ecosystems Recovery Team. Sponsored by the Habitat Stewardship Program, Gov. Can., and Nat. Conservancy Can. Victoria, BC. 11 pp. |
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Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.
Suggested Citation:
B.C. Conservation Data Centre. Species Summary: Microseris bigelovii. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 5, 2026).