Listera convallarioides
Author: (Sw.) Nutt. ex Ell.

Broad-leaved twayblade

Orchidaceae (orchid family)

Close up of Listera convallarioides by Susan Spackman Panjabi.

Close up of Listera convallarioides by Susan Spackman Panjabi.
Close up of Listera convallarioides by Susan Spackman Panjabi.

Ranks and Status

Global rank: G5
State rank: S2
Federal protection status: None
State protection status: None

Description and Phenology

Listera convallarioides from USDA PLANTS database, Britton and Brown 2013; see also Weber and Wittmann 2012.

General description: Broad-lipped twayblade is a small, inconspicuous perennial orchid, 5-37 cm tall with two, opposite, elliptic to nearly round, green leaves that are perpendicular to the stem, and 2-7 cm long. The stem above the leaves is whitish glandular hairy with up to 20 flowers, which are yellowish-green, faintly tinged with purple. Small green sepals and petals bend back from the dominant lip that is about 1.5 cm long, narrow at the base and wide at the tip. Two shallow lobes at the tip make the lip resemble the folded wings of an insect. Sometimes there is a small tooth between the lobes. Fruit capsules are ellipsoid, 8x5 mm, glabrous. Reproduction by runners sometimes produces large colonies of plants (Flora of North America 2002, Culver and Lemly 2013, Ackerfield 2015).

Look Alikes: The round, opposite leaves, and lip petal that gradually narrows to the base distinguish this species from other local orchids (Culver and Lemly 2013, Ackerfield 2015).

Phenology: Flowers June-August in Colorado (Ackerfield 2015).


Habitat of Listera convallarioides by Susan Spackman Panjabi.

Habitat of Listera convallarioides by Susan Spackman Panjabi.

In Colorado, this species is found in shady, moist forests, and along streams (Culver and Lemly 2013, Ackerfield 2015). Associated taxa include: Picea engelmannii, Abies bifolia, Acer negundo, Populus tremuloides, Pseudotsuga menziesii, Betula occidentalis, Corylus cornuta, Lonicera involucrata, Rudbeckia spp., Cystopteris fragilis, Actaea rubra, Circaea alpina, Sanicula marilandica, Oryzopsis asperifolia, Streptopus amplexifolius, Botrychium virginianum, Rubus pubescens, Equisetum spp., Thalictrum fendleri, Corallorhiza maculatam, Glyceria elata, Smilacina stellata, Streptopus fassetti, Carex utriculata. Mertensia ciliata, Limnorchis sp., Acer glabrum, Glyceria elata, Maianthemum stellatum, moss.

Elevation Range: 6,732 - 9,455 feet (2,052 - 2,882 meters)


Colorado endemic: No
Global range: In eastern North America, this ranges from Newfoundland to southern Quebec, southern Ontario, and northeastern Minnesota, south to the northern sections of Wisconsin, Michigan, New York, Vermont, and Maine. In western North America, this ranges from southern British Columbia south to the high elevations of California, Arizona, Neveda, Utah, and Colorado. It is disjunct to South Dakota and scattered locations in northern British Columbia and the Aleutians  (Flora of North America Editorial Committee 2002).
State range: In Colorado, in Boulder, Custer, Gilpin, Gunnison, Jackson, Larimer, Pitkin, Rio Blanco, and Routt counties. However, not all county records have voucher specimens.
Distribution of Listera convallarioides in Colorado according to mapped land ownership/management boundaries (CNHP 2017, COMaP).

Distribution of Listera convallarioidesin Colorado.

Threats and Management Issues

Four occurrences report no threats. One occurrence reports grazing as a possible threat. Colorado climate scenarios for 2050 suggest temperature will increase by 3-7 F and precipitation may decrease or increase. The impact to any given rare plant habitat is likely to vary. Long-term monitoring that includes weather and soil moisture data is critical to understanding climate impacts.


    • Beardsley, M. and D. A. Steingraeber. 2013. Population dynamics, rarity and risk of extirpation for populations of Mimulus gemmiparus (budding monkeyflower) on National Forests of Colorado. A research report submitted to the USFS Forest Service. Arapaho and Roosevelt National Forets and Pawnee National Grassland. pp 17. Accessed online on May 11 at: documents/USFS_MimulusStatusReport2013.pdf
    • Britton, N. L. and A. Brown. 1913. An Illustrated Flora of the Northern United States and Canada. 3 vol. Dover Publications, Inc., N. Y. 2052 pp.
    • Colorado Native Plant Society. 1989. Rare plants of Colorado. Rocky Mountain Nature Association, Colorado Native Plant Society, Estes Park, Colorado. 73 pp.
    • Colorado Natural Heritage Program and the Geospatial Centroid. 2017. The Colorado Ownership and Protection Map (COMaP). Colorado State University, Ft. Collins, CO.
    • Cronquist, A., A. H. Holmgren, N. H. Holmgren, J. L. Reveal and P. K. Holmgren. 1977. Intermountain Flora Vascular Plants of the Intermountain West, USA: vol. 6. New York Botanical Garden, Bronx, NY.
    • Culver, D. R. and J. M. Lemly. 2013. Field Guide to Colorado's Wetland Plants. Colorado Natural Heritage Program. Colorado State University. 694 pp.
    • Flora of North America Editorial Committee. 2002. Flora of North America North of Mexico. Vol. 26. Magnoliophyta: Liliidae: Liliales and Orchidales. Oxford Univ. Press, New York. xxvi + 723 pp.
    • Harrington, H. D. 1954. Manual of the Plants of Colorado. Sage Books, Denver, CO. 666 pp.
    • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
    • USDA, Natural Resources Conservation Service, PLANTS Database [USDA PLANTS]. Accessed 2017.
    • Weber, W. A. and R. C. Wittmann. 2012. Colorado Flora, Eastern Slope, A Field Guide to the Vascular Plants, Fourth Edition. Boulder, Colorado. 555 pp.
    • Weber, W. A. and R. C. Wittmann. 2012. Colorado Flora, Western Slope, A Field Guide to the Vascular Plants, Fourth Edition. Boulder, Colorado. 532 pp.
    • Welsh, S. L. 1974. Anderson's Flora of Alaska and Adjacent Canada. Brigham Young University Press, Provo, UT.

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