Do mycorrhizal fungi explain the rarity of Dendrophylax lindenii, the Ghost Orchid?
More than half of the 210 species of native North American orchids are endangered. One of these, Dendrophylax lindenii, the Ghost Orchid, is restricted to southwestern Florida and far western Cuba. It is a leafless epiphyte that grows on a restricted set of tree species, two in Florida and up to 13 in Cuba. While pollinators influence the broad scale distribution of orchid species, other factors drive fine scale distributions. The leafless morphology of D. lindenii suggests that it has a high dependency on orchid mycorrhizal fungi because of its reduced photosynthetic capacity compared to orchids with leaves. Understanding the distribution of the mycorrhizal fungi colonizing the orchid in relation to its host trees (phorophytes) will provide insights into its distribution and information important to its conservation. To address this potential driver of the fine scale distribution of the Ghost Orchid I am investigating the mycorrhizal fungi colonizing Ghost Orchid roots and the bark of its phorophytes.
I am also investigating its dependence on mycorrhizal fungi for carbon resources using stable isotope analyses. My work to date focuses on the Florida population. The results will add to our understanding of the biology of epiphytic, leafless orchids and will generate recommendations for conservation of Ghost Orchids and other epiphytic orchids.