Northern Prairie Wildlife Research Center
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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U.S. Geological Survey