''Corallorhiza mertensiana'', or Pacific coralroot, is a coralroot orchid native to the shady conifer forests of northwestern

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. It also goes by the common names Western coralroot and Mertens' coralroot.Turner, Mark & Phyllis Gustafson. Wildflowers of the Pacific Northwest. Timber Press Field Guide. ''Corallorhiza mertensiana'' was previously considered a subspecies of ''

Corallorhiza maculata ''Corallorhiza maculata'', or spotted coralroot, is a North American coralroot orchid. It has three varieties: ''C. maculata var. occidentalis'' (western spotted coralroot), ''C. maculata var. maculata'' (eastern spotted coralroot or summer cor ...

'' but was given species rank in 1997 by Freudenstein.

Description

''Corallorrhiza mertensiana'' is a leafless, parasitic, perennial orchid that is 6-20 inches tall. The stem is red to brownish purple. The upper petals are pink to reddish pink, with yellow to dark red veins. The lower petals are wider, dark pink to red, and have three deep red veins. Beneath the lower petal the spur is prominent. The flower spikes are visible from May to August. ''Corallorrhiza mertensiana'' has no roots, only hard, branched rhizomes that resemble coral.

Fungal associations

''Corallorrhiza mertensiana'' is a nonphotosynthetic,

myco-heterotroph Myco-heterotrophy (from Greek μύκης , "fungus", ἕτερος ', "another", "different" and τροφή ', "nutrition") is a symbiotic relationship between certain kinds of plants and fungi, in which the plant gets all or part of its food fro ...

that receives its nutrition from ectomycorrhizal fungi. The fungi receive mineral nutrients and carbon symbiotically from trees. ''Corallorrhiza mertensiana'' parasitizes the carbon from the fungi. ''Corallorrhiza mertensiana'' only associates with mutually exclusive subsets of species from the

Russulaceae The Russulaceae are a diverse family of fungi in the order Russulales, with roughly 1,900 known species and a worldwide distribution. They comprise the brittlegills and the milk-caps, well-known mushroom-forming fungi that include some edible ...

. ''Corallorrhiza mertensiana'' never shares fungal species with '' Corallorrhiza maculata'' even when intermixed at the same growing site.

Habitat and distribution

''Corallorrhiza mertensiana'' grows in shady coniferous forests at low to mid-elevations. It prefers damp soil that is rich in humus, and receives dappled sunlight. ''Corallorrhiza mertensiana'' is found in the Cascades from

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, and the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...

from

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

. In a survey of the plants found in Glacier Bay, Alaska in 1923, ''Corallorhiza mertensiana'' was reported to be growing beneath the thickets of ''Alnus tenuifolia'' along with ''Petasites frigida'', ''Aspidium'', and ''

Polystichum ''Polystichum'' is a genus of ferns in the family Dryopteridaceae, subfamily Dryopteridoideae, according to the Pteridophyte Phylogeny Group classification of 2016 (PPG I). The genus has about 500 species and has a cosmopolitan distribution. The ...

''. In

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

it has been found to be associated with ''Gaultheria shallon'', ''Hylocomium splendens'', and ''Rhytidiadelphus loreus''.Ceska, A., & A.M. Scagel. Indicator Plants of Coastal British Columbia. UBC Press. 2011.

Gallery

File:Corallorhiza_mertensiana_9316.JPG

References

External links

* *
Jepson Manual treatment - ''Corallorhiza mertensiana''

Mycorrhizal Specialization: ''Corallorhiza mertensiana'' and ''Corallorhiza maculata''
{{Taxonbar, from=Q1596692 mertensiana Orchids of Canada Orchids of the United States Flora of the Northwestern United States Flora of Western Canada Plants described in 1833 Flora without expected TNC conservation status