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Confocal Microscopy Image Gallery
Plant Tissue Autofluorescence Gallery
Orchid Root
Orchids are a diverse family (Orchidaceae) of perennial plants highly valued in the florist industry for their striking, exotic flowers. Their common name stems from the Greek word orchis, meaning "testicle", which is suggestive of the shape of the root tubers some members of the family develop.
The roots of a number of orchid species have a symbiotic relationship with specialized fungi, and the tiny seeds of the plants require interaction with fungi to germinate naturally. More than 15,000 orchid species are recognized, most of which inhabit tropical regions, though some can be found in nearly all nonpolar locales. In several areas, rare orchids that garner particularly high prices have been collected to such a great extent that protections have been put in place to save them from extinction.
The tremendous array of adaptations exhibited by orchids is an evolutionary wonder. The plants can grow in trees (epiphytes) and on rocks (lithophtyes) as well as in the earth (terrestrials), and their flowers often exhibit highly developed means of attracting pollinating insects and guaranteeing cross-pollination. For instance, the design of the lady’s slipper (Cypripedium species) obliges insects that attempt to obtain nectar from its flowers to come into direct physical contact with both the plant’s male and female reproductive organs, while the dark labellum of another species, the bumblebee orchid (Ophrys bombyliflora), looks so similar to an insect that male bumblebees regularly attempt to mate with it and become covered with pollen during the process.
Contributing Authors
Nathan S. Claxton, Shannon H. Neaves, and Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.