1. Family: Orchidaceae Juss.
    1. Genus: Platanthera Rich.
      1. Platanthera obtusata (Banks ex Pursh) Lindl.

        This species is accepted, and its native range is Subarctic America to Rocky Mountains.

    [O-EM]
    Diagnostic

    The rare Eurasian Platanthera obtusata subsp. oligantha (Turczaninow) Hultén differs from the North American subsp. obtusata in its smaller dimensions and rhombic-lanceolate lip. It is also said to be densely few-flowered, although some Siberian material is comparable to American plants. Supposedly intermediate plants are reported from Alaska, and much material from that area is reduced in stature and with smaller flowers than typical of American plants. In most cases, however, lips are relatively slender, and the plants seem merely to be stunted by their environment. One or two collections from the Alaskan Peninsula and Aleutians, however, seem entirely referable to subsp. oligantha with dense, few-flowered inflorescences of very small flowers with rhombic-lanceolate lips and shorter curved spurs. Eurasian plants are reported to be hexaploid or perhaps sometimes triploid, and if the apparent ploidy differences delimit the taxa, then it should be possible to unequivocally identify Alaskan plants.

    General Description

    Plants 5.5–35 cm. Leaves 1(–2, rarely), spreading-ascending on base of stem; bracts 0(–1, rarely); blade linear-oblanceolate, elliptic, or broadly obovate, 3.5–15 × 0.8–5 cm. Spikes lax. Flowers resupinate, not showy, greenish white to yellowish green; corolla commonly whiter than calyx; lateral sepals reflexed; petals rhombic, lanceolate-falcate, margins entire; lip descending, linear, narrowly lance-rhombic, or linear-hastate, with median basal thickening, unlobed, 2.5–8(–10) × less than 1–2 mm, margins entire; spur slenderly conic, 3–8(–10) mm; rostellum lobes directed forward, wide-spreading, rounded-angular; pollinaria straight; pollinia remaining enclosed in anther sacs; viscidia orbiculate; ovary rather slender to stout, mostly 3–10 mm. 2n = 42, 63 (American, as Habenaria obtusata), 126 (Eurasian, as Habenaria obtusata).

    Habitat

    Mesic to wet coniferous forest, forested fens, sphagnum bogs, stream banks, tundra, moist roadsides; 0--3500 m.

    Distribution

    Native to:

    Alaska, Alberta, Aleutian Is., British Columbia, Colorado, Idaho, Labrador, Maine, Manitoba, Masachusettes, Michigan, Minnesota, Montana, New Brunswick, New Hampshire, New Mexico, New York, Newfoundland, Northwest Territorie, Nova Scotia, Nunavut, Ontario, Prince Edward I., Québec, Saskatchewan, Utah, Vermont, Washington, Wisconsin, Wyoming, Yukon

    Platanthera obtusata (Banks ex Pursh) Lindl. appears in other Kew resources:

    First published in Gen. Sp. Orchid. Pl.: 284 (1835)

    Accepted by

    • Efimov, P.G. (2016). A revision of Platanthera (Orchidaceae: Orchidoideae; Orchidaceae) in Asia Phytotaxa 254: 1-233.
    • Gillespie, L.J. & al. (2015). New vascular plant records for the Canadian Arctic Archipelago PhytoKeys 52: 23-79.
    • Allred, K.W. (2012). Flora Neomexicana, ed. 2, 1: 1-599. Range Science Herbarium, Las Cruces, New Mexico.
    • Govaerts, R. (2003). World Checklist of Monocotyledons Database in ACCESS: 1-71827. The Board of Trustees of the Royal Botanic Gardens, Kew.

    Literature

    Kew Backbone Distributions
    • Allred, K.W. (2012). Flora Neomexicana, ed. 2, 1: 1-599. Range Science Herbarium, Las Cruces, New Mexico.
    Orchideae: e-monocot.org
    • Romero-González, G.A., Fernández-Concha, G.C., Dressler, R.L., Magrath, L.K. & Argus, G.W. Orchidaceae. Magnoliophyta: Liliidae: Liliales and Orchidales (2002).at

    Sources

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Orchideae: e-monocot.org
    All Rights Reserved