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Aquatic and Wetland Vascular Plants of the Northern Great Plains

Orchidaceae - The Orchid Family


Perennial herbs from rather fleshy, strongly mycorhizal roots. Leaves simple, cauline and alternate or mostly basal, sessile and usually sheathing the stem, parallel-veined. Inflorescence of 1 or 2 terminal blossoms or of few to many flowers in a terminal bracteate spike or raceme. Flowers perfect, strongly irregular, epigynous, very showy in some spp.; perianth comprised of 6 segments, although this is sometimes obscured by fusion; calyx consisting of the uppermost segment and the 2 outermost lateral segments, the sepals sometimes resembling the lateral petals, the lateral sepals free or (in Cypripedium) connate to form a single appendage below the lip or (in Spiranthes) connivent with the lateral petals to form a hood over the lip; corolla white or otherwise colored, the 2 lateral petals alike, the third petal (the lowermost perianth segment) typically modified and referred to as the lip; stamens 1 or 2, attached to the style and along with the style and stigma forming a short to prominent column, the stigma borne on the lower side near the base of the column, pollen shed in waxy pollinia; ovary inferior, 1-celled, with 3 parietal placentae, or 3-celled, maturing into a many-seeded capsule, the seeds very numerous and minute. The second largest family (or largest by some estimates) of vascular plants, with most representatives occurring in the tropics where many grow as epiphytes.

Within the Orchidaceae are a few of our most beautiful and rarest wildflowers, such as the ladyslippers (Cypripedium spp.) and the prairie fringed orchid (Platanthera praeclara). The latter has recently been listed as an endangered species by the federal government.

References:
  
Luer, C. A.  1975.  The native orchids of the United States and Canada 
     excluding Florida.  The New York Botanical Garden

Magrath, L. K.  1973.  The native orchids of the prairies and plains region 
     of North America.  Unpubl. Ph.D. thesis, Univ. Kans., Lawrence. 

Lead Characteristic Go To
1 Flowers 1 or 2 per stem, the lip much inflated and pouchlike. Genus Cypripedium
1 Flowers few to many (2-12 in Liparis) in a bracteate spike or raceme, the lip not inflated. Lead 2
2 Perianth prolonged backward into a spur. Lead 3
2 Perianth not spurred. Lead 4
3 Spur pouchlike, 2-3 mm long. Genus Coeloglossum
3 Spur cylindric, 4-50 mm long. Genus Platanthera
4 Flowers in a loose raceme; foliage leaves consisting of a pair of basal leaves. Genus Liparis
4 Flowers in a twisted spike; foliage leaves best developed at the base and reduced upward on the stem. Genus Spiranthes

69. Orchidaceae, the Orchid Family
1. Coeloglossum Hartman
1. Coeloglossum viride (L.) Hartman -- Long-bracted orchid
2. Cypripedium L. -- Ladyslipper
1. Cypripedium calceolus L. -- Yellow ladyslipper
2. Cypripedium candidum Muhl. -- White ladyslipper.
3. Cypripedium reginae Walt. -- Showy ladyslipper
3. Liparis Rich. -- Twayblade
1. Liparis loeselii (L.) Rich.
4. Platanthera Rich.
1. Platanthera hyperborea (L.) Lindl. -- Northern green orchid
2. Platanthera praeclara Sheviak & Bowles -- Western prairie fringed orchid
5. Spiranthes Rich. -- Ladies'-tresses
1. Spiranthes cernua (L.) Rich. -- Nodding ladies'-tresses
2. Spiranthes magnicamporum Sheviak -- Great Plains ladies'-tresses
3. Spiranthes romanzoffiana Cham. -- Hooded ladies'-tresses
4. Spiranthes vernalis Engelm. & A. Gray -- Spring ladies'-tresses


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