Plant of the Week
Three Birds Orchid (Triphora trianthophora)
By Thomas C Philipps
Three birds orchid (Triphora trianthophora) is an unusual orchid of deciduous forests ranging across much of central and eastern North America. The common name, three birds orchid, is attributed to the flower's resemblance to three birds in flight. The scientific name, trianthophora, means "bearing three flowers," which refers to the typical number on each plant. The pink and white flowers are quite small, rarely reaching 2 cm. in size and the stems vary greatly in length perhaps due to local light and moisture conditions. In some instances stems barely reach the surface of the leaf liter (about 5 cm.), and on other occasions grow up to 20 cm. tall. What this species lacks in size it makes up for in mystery and beauty. The striking flower shape and color often stand out in sharp contrast to the deep and dappled shade of the deciduous forests it occupies.
Three birds orchid occupies a habitat that is seemingly inhospitable to most other plants: American beech forests. It is a denizen of nearly pure stands of American beech (Fagus grandifolia) forests that typically have a smattering of another inhospitable species: eastern hemlock (Tsuga canadensis). The plants tend to congregate in small depressions on the forest floor that is lined with deep layers of decaying leaves. In New England almost all known populations occur on south facing slopes, although this may be a matter of climate in northern portions of its range.
The species is found in the United States from Maine west to Wisconsin and Nebraska, south to Texas and Florida. It also occurs in the Province of Ontario in Canada. It is uncommon throughout much of this range and is listed as endangered or threatened in Maine, New Hampshire, Vermont, New York, Pennsylvania, Ohio, Michigan, Massachusetts, New Jersey, Maryland, and Florida. It was thought to be extirpated in Connecticut, but a recent discovery of a previously unknown population has restored it to that state's flora. Three birds orchid occurs on the Shawnee, Monongahela, and White Mountain national forests in the eastern region, and is considered a regional forester's sensitive species on the Monongahela and White Mountain national forests. Although rare in many states it is often locally abundant. Populations on the White Mountain national forest in New Hampshire often range into the hundreds and even thousands of plants in any given year. As with many orchid species, populations often vary greatly from year to year due the species ability to remain dormant underground for many years without sending up a shoot.
Three birds orchid is secretive and there is plenty of advice out there on when to go looking for the species. One tale has it that the best time to find the species in bloom is to search beech forests during the first week following the first drenching rain of August. The fact is three birds orchid is extremely ephemeral; appearing only for a short period of time in late summer typically from mid-August to mid-September. The floral beauty is fleeting; the bloom period is short sometimes lasting only a few days in a population. Each plant typically produces three flowers with each flower remaining fresh and viable for only a single day. Flowering tends to be synchronous with most plants within a population blooming at the same time. This synchronized bloom may be an adaptation to ensure successful pollination. A single bloom may not put on enough of a show to attract the appropriate pollinator, but many plants blooming in concert put on quite a show!
For More Information
NatureServe. 2006. NatureServe Explorer: An Online Encyclopedia of Life [Enter Triphora trianthophora in the Species Quick Search]. NatureServe, Arlington, Virginia.
Ramstetter, Jennifer M. 2001. New England Plant Conservation Program Conservation and Research Plan, Triphora trianthophora (Swartz) Rydb, Three-birds Orchid (PDF, 168 KB). New England Wild Flower Society, Framingham, Massachusetts, USA.
White Mountain National Forest. 2006. Unpublished Monitoring Data for Triphora trianthophora occurrences. White Mountain National Forest, Laconia, New Hampshire.