Corallorhiza is a genus in the Orchidaceae family from North and Central America. It is commonly known as coralroot because its rhizome branches are short and scaly and resemble a marine coral. These plants are more or less dependent on orchid associated fungi called orchid mycorrhizae. The latest evidence shows that these fungi are not necessarily saprobic (where they gather nutrients from the surrounding organic matter and giving it to the orchids), but are mycorrhizal. The orchids are in fact parasites of these fungi which are symbiotic with trees. In other words, ectomycorrhizal fungi are symbiotic with trees where they obtain mineral nutrients for carbons fixed through photosynthesis. The orchids behave like a parasite that steals the carbon from the fungus. This fascinating symbiosis is complex and is one of the hottest topics of mycorrhizal research as of 2008.
Corallorhiza maculata is found in shaded coniferous forests from California to British Columbia, also in the eastern United States and New Mexico. It has red brown to pink spotted petals and a white spotted lip. The first photo by Bob Rutemoeller was taken in Kruse Rhododendron State Park and the next photos by by Mary Sue Ittner in Mendocino County. The last three were taken by Nhu Nguyen in Tilden Park, Berkeley CA under some native oaks in spring. The species can be variable, some with spots and these are without spots.
Corallorhiza mertensiana is found in shaded to open mixed-evergreen or coniferous forests in decomposing litter. It has pink to red sepals. Photos taken by Bob Rutemoeller in Kruse Rhododendron State Park and Salt Point State Park, California.
Corallorhiza striata occurs in similar places to C. maculata. It too is a saprophyte with stripes instead of spots on the flower parts.
Corallorhiza wisteriana is found in mixed deciduous forests in the southeastern United States. Its survival is based through a relationship with a fungus or fungi which decompose forest litter and the plants have no foliage or photosynthetic parts. Flowers appear variably in January and February in the Florida panhandle where these photos were taken. Note the camouflaged nature of the flowers. Photos by Alani Davis.
Return to the PBS wiki Photographs And Information page