Orchids can be found on every continent except Antarctica and comprise about 10% of all plant species (that statistic surprised me). Extremely sensitive to environmental changes and habitat loss, many native orchids have become extremely rare, resulting in a black-market among orchid fanciers and purveyors. Unfortunately this illegal orchid trade, described well by Eric Hansen in his book Orchid Fever (which I read about ten years ago), results in endangered or threatened orchids which do not survive upon reaching their destination. One reason for a high mortality rate among transplanted orchids is a lack of mycorrhizal fungi.
Early in their lives native orchids depend on microscopic fungi for nourishment. These fungi, known as mycorrhizal fungi, are necessary for their very small, almost microscopic, seeds to germinate. After germination, the fungi grow into the roots of the orchid, which digests the fungi in order to obtain nutrients. This relationship is necessary for the orchid to thrive.
In the April 2012 Scientific American was an interesting report about the orchid/fungi relationship. One of the orchids studied is a very close relative of the rattlesnake orchid (Goodyera oblongifolia) that I mentioned last year. The genus is the same, both orchids have the same mottled leaves, similar white flowers and are found in old forests.
The results of their study showed that only old forests had enough of the root fungi to germinate Goodyera seeds and maintain healthy orchid plants. The presence of the necessary fungi was not enough, the fungi had to be present in abundant quantities. Adding the particular fungi necessary for Goodyera to the soil in younger forests did not induce germination. In addition, older forests had more mycorrhizal diversity than younger forests.
Rattlesnake orchids are found in old coniferous forests (these photographs were taken along the North Umpqua Trail OR). As with other orchid species, removing the orchid from its natural habitat and planting it in a potting medium without its specific root fungi can result in the death of this beautiful wildflower. Native orchids should only be admired in their natural setting.
The cultivated orchids found in flower shops and nurseries, and which many of us enjoy in our homes, are not the “native” orchid of the study.