Tubercled orchid (Platanthera flava)

Description

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Tubercled orchid fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Tubercled orchid description

The tubercled orchid (Platanthera flava) is one of the rarer species of orchid in the north-eastern United States. Its sweet, perfume-like fragrance is often detected before the plant itself, as its largely greenish colouration makes this species rather inconspicuous ⁽³⁾. 

Like other orchids, the tubercled orchid has flowers with three petals and three sepals. The lower sepal is modified into a ‘lip’ with a slender spur. In the tubercled orchid, the lip is oblong and bears a tubercle on the surface, which distinguishes it from other, similar orchids ⁽⁴⁾. The flowers of the tubercled orchid are white, stiff, compact and clustered together to form an inflorescence ^{(2) (5)}. 

The leaves of the tubercled orchid occur only along the hairless stem and are lance-like in shape ⁽⁶⁾. Plants growing directly in sunlight have yellow-green leaves, but those in the shade have dark green leaves ⁽⁵⁾.

Also known as

northern tubercled orchid, pale green orchid, southern rein orchid, tubercled rein-orchid.

Size

Height: 10 - 60 cm ⁽²⁾

Tubercled orchid biology

The tubercled orchid is a perennial species ⁽⁶⁾. Its flowers bloom from June to September ⁽⁶⁾. The flowers are pollinated by moths and mosquitoes, and seeds are produced in August ⁽⁵⁾.

Tubercled orchid range

The tubercled orchid is widespread in the north-eastern United States ⁽⁴⁾, where it ranges from Nova Scotia in Canada, and New England, New York, Pennsylvania, New Jersey and Minnesota in the U.S., south to Missouri, Georgia and the southern Appalachian Mountains ⁽³⁾.

Tubercled orchid habitat

The tubercled orchid prefers wet to moist, slightly acidic to slightly alkaline soils in bogs, swamps, floodplains, meadows and prairies ^{(2) (6)}. It may also be found on peaty or sandy soils along the margins of lakes, rivers and ponds ^{(2) (4)}.

Tubercled orchid status

The tubercled orchid has not yet been assessed by the IUCN.

Tubercled orchid threats

Although widespread in the north-eastern U.S., the tubercled orchid is rare or threatened in many parts of its range. Its distribution is often limited by the availability of its habitat, which is vulnerable to land conversion as a result of expanding residential, commercial and agricultural developments. The tubercled orchid is also potentially threatened by herbicide spraying and picking by unscrupulous orchid collectors ⁽⁴⁾.

Tubercled orchid conservation

The tubercled orchid has not been the target of any known conservation measures.

Find out more

Find out more about the tubercled orchid:

• University of Wisconsin-Madison: Department of Botany - Tubercled orchid:
  http://www.botany.wisc.edu/orchids/flava.html

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Glossary

Inflorescence

The reproductive shoot of a plant, which bears a group or cluster of flowers.

Perennial

Plants that live for at least three seasons; after an initial period they produce flowers once a year.

Pollinate

To transfer pollen grains from the stamen (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant.

Prairie

An extensive area of flat or rolling, predominantly treeless grassland, especially the large tract or plain of central North America.

Sepal

A leaf-like, usually green part of the protective outer layer of a flower bud.

Tubercle

A small, rounded, wart-like bump on the skin or on a bone.

References

1. Species 2000 and ITIS (July, 2011)
   http://www.catalogueoflife.org/
2. University of Wisconsin-Madison: Department of Botany (July, 2011)
   http://www.botany.wisc.edu/orchids/flava.html
3. Brown, P.M. (1997) Wild Orchids of the Northeastern United States: A Field Guide. Cornell University Press, Ithaca, New York.
4. Coffin, B. and Pfannmuller, L. (1988) Minnesota's Endangered Flora and Fauna. University of Minnesota Press, Minnesota.
5. Fowler, J.A. (2005) Wild Orchids of South Carolina: A Popular Natural History. University of South Carolina Press, South Carolina.
6. Robert W. Freckmann Herbarium - Platanthera flava (July, 2011)
   http://wisplants.uwsp.edu/scripts/detail.asp?SpCode=PLAFLAvHER