Nodding Pogonia

Triphora trianthophora (Sw.) Rydb.

Triphora trianthophora
Alfred Schotz

Monocotyledoneae (Monocots)
Orchidaceae (Orchid Family)
State Protection
Listed as Threatened by New York State: likely to become Endangered in the foreseeable future. For animals, taking, importation, transportation, or possession is prohibited, except under license or permit. For plants, removal or damage without the consent of the landowner is prohibited.
Federal Protection
Not Listed
State Conservation Status Rank
Imperiled in New York - Very vulnerable to disappearing from New York due to rarity or other factors; typically 6 to 20 populations or locations in New York, very few individuals, very restricted range, few remaining acres (or miles of stream), and/or steep declines.
Global Conservation Status Rank
Apparently Secure globally (most likely) - Conservation status is uncertain, but most likely uncommon in the world but not rare; usually widespread, but may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors. More information is needed to assign a firm conservation status.


Did you know?

A population of this orchid was recently found in Cayuga County at the exact spot where it was previously collected in 1919. It may be underreported in the state because the time when it is blooming and visible is so short (typically the whole population flowers synchronously, and flowers last only one day) and it may not bloom every year. The flowers do not have nectar and may bloom all at once to ensure pollination before the pollinators learn to avoid flowers with no reward. According to one botanist, this synchronicity apparently extends over great areas, because during 1990 Triphora was observed flowering on the exact same day in New Hampshire, Maine, and Massachusetts.

State Ranking Justification

There are nine existing populations but two of them are small. This plant is very difficult to survey because of the limited time it blooms so it is expected that more populations will be found. There are 37 historical populations.

Short-term Trends

Numbers of plants are probably stable but only a couple of occurrences have been monitored over the short term. The flowering biology of this plant makes it difficult to assess trends.

Long-term Trends

There are many more historical records than current known locations so it appears that this orchid has been declining. However, populations are difficult to survey because the window of opportunity to see the plants is so small.

Conservation and Management


No current threats are known for this species since little is known about their natural history here. Populations occur in areas where there is little development.

Conservation Strategies and Management Practices

Sites should be monitored to determine threats and health trends.

Research Needs

Research is needed to determine the factors affecting bloom time and frequency. The effect of deer browse, if any, should be studied. Physical and chemical parameters of their preferred sites should be studied to help locate additional populations.



An ephemeral plant of dry to moist areas of beech-maple mesic forests, in moist leaf-mold pockets of mixed hardwood forests, hemlock-northern hardwood forests within shale ravine systems, deep mucky soil under yellow birch, sandy woods within the Great Lakes Plains, and white cedar-tamarack swamps (New York Natural Heritage Program 2004). Dry-mesic to mesophytic forests over sandstone or limestone, sandy oak-mixed hardwood forests, seasonally wet and sandy flatwoods, Great Lakes dune forests, coniferous forests, tamarack swamps, rhododendron thickets, floodplain forests, wet muck in glacial lake bed forests, and in seasonally flooded sinkhole swamps (Flora of North America 2002). Rare in humus-rich, moist forests (Rhoads and Block 2000). Rich moist woods, often on rotten logs (Gleason and Cronquist 1991). Humus of beech, oak, maple, or mixed woods (Voss 1972). Humus of hardwood-forests (Fernald 1970).

Associated Ecological Communities

  • Appalachian oak-hickory forest* (guide)
    A hardwood forest that occurs on well-drained sites, usually on ridgetops, upper slopes, or south- and west-facing slopes. The soils are usually loams or sandy loams. This is a broadly defined forest community with several regional and edaphic variants. The dominant trees include red oak, white oak, and/or black oak. Mixed with the oaks, usually at lower densities, are pignut, shagbark, and/or sweet pignut hickory.
  • Beech-maple mesic forest (guide)
    A hardwood forest with sugar maple and American beech codominant. This is a broadly defined community type with several variants. These forests occur on moist, well-drained, usually acid soils. Common associates are yellow birch, white ash, hop hornbeam, and red maple.
  • Hemlock-hardwood swamp (guide)
    A swamp that occurs on mineral soils and deep muck in depressions which receive groundwater discharge. These swamps usually have a fairly closed canopy (70 to 90% cover), sparse shrub layer, and low species diversity. The tree canopy is typically dominated by eastern hemlock and co-dominated by yellow birch and red maple.
  • Hemlock-northern hardwood forest* (guide)
    A mixed forest that typically occurs on middle to lower slopes of ravines, on cool, mid-elevation slopes, and on moist, well-drained sites at the margins of swamps. Eastern hemlock is present and is often the most abundant tree in the forest.
  • Limestone woodland* (guide)
    A woodland that occurs on shallow soils over limestone bedrock in non-alvar settings, and usually includes numerous rock outcrops. There are usually several codominant trees, although one species may become dominant in any one stand.
  • Maple-basswood rich mesic forest* (guide)
    A species rich hardwood forest that typically occurs on well-drained, moist soils of circumneutral pH. Rich herbs are predominant in the ground layer and are usually correlated with calcareous bedrock, although bedrock does not have to be exposed. The dominant trees are sugar maple, basswood, and white ash.
  • Rich mesophytic forest* (guide)
    A hardwood or mixed forest that resembles the mixed mesophytic forests of the Allegheny Plateau south of New York but is less diverse. It occurs on rich, fine-textured, well-drained soils that are favorable for the dominance of a wide variety of tree species. A canopy with a relatively large number of codominant trees characterizes this forest. Canopy codominants include five or more of the following species: red oak, red maple, white ash, American beech, sugar maple, black cherry, cucumber tree, and black birch.
  • Successional northern hardwoods*
    A hardwood or mixed forest that occurs on sites that have been cleared or otherwise disturbed. Canopy trees are usually relatively young in age (25-50 years old) and signs of earlier forest disturbance are often evident. Characteristic trees and shrubs include any of the following: quaking aspen, big-tooth aspen, balsam poplar, paper birch, gray birch, pin cherry, black cherry, red maple, and white pine.
  • Successional southern hardwoods*
    A hardwood or mixed forest that occurs on sites that have been cleared or otherwise disturbed. Canopy trees are usually relatively young in age (25-50 years old) and signs of earlier forest disturbance are often evident. Characteristic trees and shrubs include any of the following: American elm, slippery elm, white ash, red maple, box elder, silver maple, sassafras, gray birch, hawthorn, eastern red cedar, and choke-cherry.

* probable association but not confirmed.

Associated Species

  • Acer pensylvanicum (striped maple)
  • Acer rubrum var. rubrum (common red maple)
  • Acer saccharum (sugar maple)
  • Adiantum pedatum (maidenhair fern)
  • Aralia nudicaulis (wild sarsaparilla)
  • Betula alleghaniensis (yellow birch)
  • Betula lenta (black birch)
  • Betula papyrifera (paper birch)
  • Epifagus virginiana (beech-drops)
  • Fagus grandifolia (American beech)
  • Fraxinus americana (white ash)
  • Hamamelis virginiana (witch-hazel)
  • Hepatica nobilis var. acuta
  • Hepatica nobilis var. obtusa
  • Huperzia lucidula (shining firmoss)
  • Laportea canadensis (wood-nettle)
  • Maianthemum canadense (Canada mayflower)
  • Mitchella repens (partridge-berry)
  • Monotropa uniflora (Indian-pipe)
  • Polystichum acrostichoides (Christmas fern)
  • Quercus rubra (northern red oak)
  • Tilia americana var. americana (American basswood)
  • Trientalis borealis
  • Tsuga canadensis (eastern hemlock)


New York State Distribution

This orchid is currently known only from Zoar Valley (western New York), Tonawanda Creek drainage, and the Catskill Mountains. Historical records have been documented from scattered locations around the state. More populations than are known are likely present within the state.

Global Distribution

This orchid ranges from southern Maine to southern Wisconsin, south to Florida, eastern Texas, and Central America.

Identification Comments

General Description

This is a small, attractive orchid with a very short bloom time. The purple to green stems are 10-30 cm tall and nodding at first but straighten out as they grow. A few small, clasping, oval, green leaves can be seen along the stem which is topped by 1-3 white tubular flowers with magenta edges. The flowers turn a pinkish color as they age. The triangular lip curves down and is surrounded by four forward-facing petals.

Identifying Characteristics

An ephemeral orchid with purple to green stems 10-30 cm tall from a cluster of fleshy roots. These stems are nodding at first but straighten as it grows. The ovate leaves (1-2 cm long) are sessile on or clasping to the stem. The flowers are whitish to pale pink with magenta margins. The sepal and lateral petal are lanceolate and 1.5-2 cm long. The lip is 1.5-2 cm long with three prominent green ridges that are crisped at the tip with upturned lateral lobes.

Best Life Stage for Proper Identification

This orchid may be identified from the stem, flowers, or fruit. Due to its rarity, only a picture is needed to verify the identify. Do not collect any specimens.

Similar Species

A very unique orchid that is easy to identify but difficult to find due to its very short blooming period.

Best Time to See

This orchid blooms for a very short period sometime around the second or third week of August, with all flowers of a population blooming at the same time. These flowers usually last only for a single day. Occasionally, the blooming window is a few weeks early or late. Since this orchid is only present for a few weeks each year, or remains completely dormant during the growing season, searches can be challenging. Inventories should begin in early August with repeated visits to the search site until early September.

  • Flowering
  • Fruiting

The time of year you would expect to find Nodding Pogonia flowering and fruiting in New York.

Nodding Pogonia Images


Nodding Pogonia
Triphora trianthophora (Sw.) Rydb.

  • Kingdom Plantae
    • Phylum Anthophyta
      • Class Monocotyledoneae (Monocots)
        • Order Orchidales
          • Family Orchidaceae (Orchid Family)

Additional Common Names

  • Threebirds
  • Three-birds Orchid
  • Three Birds Orchid


  • Arethusa trianthophoros Sw.
  • Pogonia trianthophora (Sw.) BSP.
  • Triphora trianthophora ssp. trianthophora [Ours are all of this subspecies.]

Additional Resources

Best Identification Reference

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.

Other References

Fernald, M.L. 1950. Gray's manual of botany. 8th edition. D. Van Nostrand, New York. 1632 pp.

Flora of North America Editorial Committee. 2002. Flora of North America, North of Mexico. Volume 26. Magnoliophyta: Liliidae: Liliales and Orchidales. Oxford University Press, New York. 723 pp.

Holmgren, Noel. 1998. The Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York.

Mitchell, Richard S. and Gordon C. Tucker. 1997. Revised Checklist of New York State Plants. Contributions to a Flora of New York State. Checklist IV. Bulletin No. 490. New York State Museum. Albany, NY. 400 pp.

New York Natural Heritage Program. 2010. Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY.

New York Natural Heritage Program. 2024. New York Natural Heritage Program Databases. Albany, NY.

Reschke, Carol. 1990. Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi.

Rhoads, Ann F. and Timothy A. Block. 2000. The Plants of Pennsylvania, an Illustrated Manual. University of Pennsylvania Press, Philadelphia, PA.

Voss, E.G. 1972. Michigan Flora, Part I. Gymnosperms and Monocots. Cranbrook Institute of Science Bulletin 55 and the University of Michigan Herbarium. Ann Arbor. 488 pp.

Weldy, T. and D. Werier. 2010. New York flora atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research University of South Florida]. New York Flora Association, Albany, New York


About This Guide

Information for this guide was last updated on: August 28, 2019

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Triphora trianthophora. Available from: Accessed April 16, 2024.