Neottia convallarioides is a species of orchid known by the common names broad-lipped twayblade and broad-leaved twayblade. It was formerly placed in the genus Listera, but molecular phylogenetic studies have shown that Neottia nidus-avis, the bird's-nest orchid, evolved within the same group,, p. 864 and all species of Listera have been moved to Neottia.
Description It is a rhizomatous perennial herb growing 10 to 35 centimeters tall. It has one pair of green oval leaves 2 to 7 cm long near the base of the stem. The inflorescence is a small raceme of green or yellow-green flowers. Each has 3 reflexed lance-shaped sepals, 2 similar petals, and a lobed, wedge-shaped labellum that measures 9 to 13 mm long. The plant sometimes forms large colonies, creating a groundcover.Hoy, J. (2002). Conservation Assessment for Broad-leaved Twayblade (Listera convallarioides). USDA. White Mountain National Forest. It is known to hybridize with Neottia auriculata.
Taxonomy Neottia convallarioides was initially given the scientific name Epipactis convallarioides by Olof Swartz in 1800. In 1817 it was moved to the genus Neottia by Louis Claude Richard, giving the species its accepted name. Together with its genus it is classified in the family Orchidaceae. It has no accepted subspecies, but there is one among its synonyms.
Table of Synonyms Name Year Rank Notes Bifolium convallarioides 1913 species ≡ hom. Diphryllum convallarioides 1891 species ≡ hom. Diphryllum eschscholtzianum 1891 species = het. Epipactis convallarioides 1800 species ≡ hom. Listera convallarioides 1818 species ≡ hom. Listera convallarioides subsp. euconvallarioides 1925 subspecies ≡ hom., not validly publ. Listera convallarioides f. trifolia 1995 form = het. Listera eschscholziana 1828 species = het. Neottia convallarioides f. trifolia 2019 form = het. Neottia eschscholziana 1841 species = het. Ophrys convallarioides 1905 species ≡ hom. Serapias convallarioides 1821 species ≡ hom. Notes: ≡ homotypic synonym; = heterotypic synonym
Distribution and habitat Neottia convallarioides can be found in moist habitats such as woods, forests, swamps, and streambanks. It is native to much of Canada and in parts of the United States (Alaska, the Great Lakes Region, New England, and the mountains of the West: Rockies, Cascades, Sierra Nevada, etc.). It also reportedly occurs in Saint Pierre and Miquelon and on the Komandor Islands in the Bering Sea, part of the Russian Far East.Flora of North America v 26 p 590, Broad-leaved twayblade, Listera convallarioides (Swartz) Nuttall ex Elliott, Sketch Bot. S. Carolina. 2: 494. 1823. Biota of North America Program, 2013 county distribution map, Neottia convallarioides
References
External links Jepson Manual Treatment USDA Plants Profile Flora of North America Photo gallery