Family: Orchidaceae
COSEWIC Status: Threatened
SARA Status: Threatened
Provincial Status: Red-listed
Phantom orchid at Cultus Lake, photo B. Klinkenberg
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Phantom Orchid (Cephalanthera
austiniae)
in British Columbia
Family: Orchidaceae
COSEWIC Status: Threatened SARA Status: Threatened Provincial Status: Red-listed
Phantom orchid at Cultus Lake, photo B. Klinkenberg |
Visit the E-Flora BC atlas page for this species
The phantom orchid (Cephalanthera austiniae) is the only representative of the genus Cephalanthera in North America. Although it is found in four states in the United States, it is found in Canada only in southwestern British Columbia where it occurs at the northern limit of its range. It is a species of old-growth or mature forests, and is presently known from 13 sites in British Columbia, in three locales: the Saanich Peninsula on Vancouver Island, Salt Spring Island, and in the Chilliwack area of the lower Fraser Valley. The phantom orchid is an almost totally white mycoheterotrophic species (see glossary below) that always grows in conjunction with fungi from a single fungal family: the Thelephoraceae (Taylor et al. 2002). Specifically the orchids have been found in association with the black thelephoroids (Lee pers. com. 2003), a group known to be found only in intact mature forests (Lee pers. com. 2003). The fungi, in turn, form associations with several species of trees. It is not presently known which tree species are part of the orchid-fungi-tree partnership (Lee pers. com. 2003). In protecting and managing the phantom orchid, consideration must be given to protection and management of its fungal and tree partners. It is important to recognize that the flowering stem of this species do not represent the entire plant. The orchid occurs primarily belowground and flowering stems are sent up when above ground growing conditions are favourable. Because the phantom orchid in Canada/British Columbia occurs at the northern limit of its range, fewer flowering stems are produced and capsule production is rare. In 2000, only 42 flowering stems were recorded. However, this species can send up flowering stems more than once throughout its relatively long flowering period (from early May through to mid-July), so counts of flowering stems taken on a single day do not provide actual indication of total numbers of flowering stems in a season. The total number of belowground orchid plants found at any site can only be inferred from the flowering stems. The low number of flowers, and rarity of capsule production may be a result of climatic and pollinator limitations. When growing conditions are less favourable, the species may be able to survive underground in a dormant state, similar again to the many European species of Cephalanthera, which are described as semi-saprophytic. While dormancy has not yet been demonstrated in our species of Cephalanthera, it may account for low numbers of flowering stems in a given year, or sequence of years. Population demographic research is needed to determine if belowground dormancy is actually present and to determine pollinator dynamics. The phantom orchid occurs mainly in coniferous forest habitat in British Columbia, but it also occurs in deciduous forest dominated by big-leaf maple. The orchid shows a preference for sites with little to no understorey, and hence little competition, and little to no large woody debris. It can persist in some sites with a developed understorey, although flowering stems in these sites are infrequent. Recent observations have shown that while forest cover may be variable, there is an observed preference for calcareous sites (e.g. limestone). This is a similar preference to that shown by European species of Cephalanthera, where species are known to occur on calcareous/limestone sites. In BC, we have now found the Phantom growing immediately adjacent to a limestone quarry, on limestone tailings from an old quarry, on heavily limed compost piles, and on old shell middens. However, some populations have no immediately apparent association with limestone/calcareous soils and soil sampling is needed to investigate this. In one or two instances, the phantom orchid in BC is found in grazed sites. These sites likely supported the orchid prior to the introduction of grazine and the orchid has managed to persist. The dynamics of this are not clearly understood, but is likely tied to reduced competition as an overriding factor. Additional observations have shown that flowering stems decline in numbers when grazing is removed, but this is clearly tied to increased competition as other species are able to re-establish. Presently, the phantom orchid is threatened in Canada. The few populations, few flowering stems, lack of capsule and seed production, and threats from subdivision developments (which encroach on its habitat)) and active logging leave it very vulnerable to disturbance, habitat loss, invasive species and edge effects. Although the number of known populations has risen since 1991, when the species was first studied for COSEWIC, this increase in number of sites is paralleled by an increase in threats to the populations and several subpopulations have been lost. Other threats come from mountain bike activity, and from orchid growers/hobbyists who collect the plant in attempts to cultivate it. Further study is required to determine the precise nature of its flowering and dispersal requirements. This information is critical if recovery plans for the species are to be carried out. Importantly, the phantom orchid cannot yet be grown in cultivation, which places critical importance on the protection of the few existing sites. Management actions for this species should focus on maintaining site conditions, including microclimate, and preventing direct site disturbance. Activities that open its essential forest habitat, thus exposing populations to edge effects, open the canopy, or remove potential partners trees should be strictly controlled. This species and its fungal partner are species of mature and old growth forests, are shade dependent, and are sensitive to minor changes in site conditions. Because the overall area of occupancy for this species in BC/Canada is very small, all efforts should be made to protect and retain specific sites and site growing conditions where the orchids occur. Visit E-Flora BC for more details on the phantom orchid, and the BC Species Explorer for provincial summary information on this species.
Glossary Mycoheterotrophic: species that lack chlorophyll and are epiparasitic Epiparasites: Organism that is parasitic on another organism, that then parasitizes a third organism.
Sources: Klinkenberg, Brian and Rose Klinkenberg, 2000. Update status report on the Phantom Orchid (Cephalanthera austiniae) in Canada. Revised report, 2000. Committee on the Status of Endangered Wildlife in Canada, Ottawa. Klinkenberg, Brian and Rose Klinkenberg, 1999. Update status report on the Phantom Orchid (Cephalanthera austiniae) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. Klinkenberg, Brian and Rose Klinkenberg, 1991. Status report on the Phantom Orchid (Cephalanthera austiniae), a threatened species in Canada. Committee on the status of endangered wildlife in Canada, Ottawa. Taylor, Lee. 2003. Personal communication. Taylor DL & Bruns TD. 1997 Independent, specialized invasions of ectomycorrhizal mutualism by two nonphotosynthetic orchids. Proceedings of the National Academy of Sciences USA 94: 4510-4515
Additional reading on mycoheterotrophic species and mychorrhizal fungi: Taylor DL, Bruns TD, Leake JR & Read DJ. 2002. Mycorrhizal specificity and function in myco-heterotrophic plants. In: The Ecology of Mycorrhizas. Ecological Studies vol. 157. Ian R. Sanders and Marcel van der Heijden, eds. pp 375-414. Berlin: Springer-Verlag. Lilleskov EA, Bruns TD, Horton TR, Taylor DL, Grogan P 2004. Detection of forest stand-level spatial structure in ectomychorrhizal fungal communties. FEMS Microbiology Ecology: 49:319-332. McKendrick SL, Leake JR, Taylor DL & Read DJ.2002 Symbiotic germination and development of the myco-heterotrophic orchid Neottia nidus-avis in nature and its requirement for locally distributed Sebacina spp. New Phytologist 154: 233-247.
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