GREATER BUTTERFLY-ORCHID

Platanthera chlorantha

(Formerly: Habenaria chlorantha) and Habenaria virescens)
Orchid Family [Orchidaceae]

month8may month8jun month8june month8jul month8july

status
statusZnative
 
flower
flower8bicolour
 
flower
flower8white
 
inner
inner8green
 
morph
morph8zygo
 
morph
morph8peloric
 
petals
petalsZ4
 
type
typeZspiked
 
stem
stem8round
 
smell
smell8sweet
sweet

June 2011, Aston Clinton, Aylesbury, Bucks Photo: © Phil And Ann Farrer
20 to 60cm tall. Two large elliptical basal leaves, shiny on the upper surface and up to five smaller pointed stem leaves. White flowers in a cylindrical spike on the upper third of the single stem. Other orchids nearby.


10th May 2009, Lot Valley, France. Photo: © Hester Coley
Between 10 to 40 flowers in a spike, which is open and not dense.


July 2007, Isle of Skye, Scotland Photo: © Phil And Ann Farrer
Flower spike has 10 - 40 white flowers born on short, slightly bulging and drooping ovaries. All sepals are white; two lateral ones which are wavy-edged, and a smaller upper central one.


17th May 2009, Lot Valley, France. Photo: © Hester Coley
Ovaries are s-shaped, fluted, twisted and green, with the flower at the end.


June 2011, Aston Clinton, Aylesbury, Bucks Photo: © Phil And Ann Farrer
The tongue is long, narrow, tapers to a rounded end and is white near the sepals merging into green at the tip. In the middle where white and green meet it is semi-translucent.


June 2011, Aston Clinton, Aylesbury, Bucks Photo: © Phil And Ann Farrer
There is a long spur at the rear of the flower, again tapering from white to green at the blunt pointed end and curving slightly downwards.


July 2007, Isle of Skye, Scotland Photo: © Phil And Ann Farrer
The two pollinia are set wide apart at the opening of the spur, which is hollow throughout its length.


June 2011, Aston Clinton, Aylesbury, Bucks Photo: © Phil And Ann Farrer
The flower ages to brown and blackish. Short leafy, triangular-shaped green bracts are in the axils where drooping ovary meet main stem.


5th June 2012, near Gourdon, Lot region of France Photo: © Kelly Finney
The well-curved spur behind each flower is an enormously long 18-27mm, possibly the longest spur of any spurred flower in relation to the size of the flower itself.


5th June 2012, near Gourdon, Lot region of France Photo: © Kelly Finney
Lateral sepals are wavy-edged and spread outwards, then downwards at the blunt tip. Two narrower upper petals, together with the single upper sepal form a cowl or hood at the top. The 8-12mm long narrow lip is translucent especially where it fades from white to pale green at the tip, which is un-divided. The pollen is yellow and on diverging stamens.


June 2011, Aston Clinton, Aylesbury, Bucks Photo: © Phil And Ann Farrer
Two elliptical basal leaves.


Easily mistaken for : Lesser Butterfly-Orchid (Platanthera bifolia) but that has the two pollinia closer together and parallel to each other rather than splayed out sideways.

Confusion: Aberrant flowers of Greater Butterfly Orchid are fairly frequent, some lacking both spur and tongue, others without lateral sepals but with a sepal-like tongue. Yet others have a spur but no tongue. Sometimes all three sepals resemble tongues.

Hybridises with : Lesser Butterfly-Orchid (Platanthera bifolia) to produce Platanthera × hybrida.

Peloric Greater Butterfly Orchids have been mis-identified as hybrids with Small-White Orchid (Pseudorchis albida). Peloric aberrations are where the normal zygomorphic symmetry is broken by the addition of other elements so as to resemble actinomorphic (radial) symmetry. However, all Orchids nominally possess zygomorphic symmetry (bi-lateral symmetry).

No relation to : Butterfly Bush, Alternate-leaved Butterfly-bush, and Weyer's Butterfly-Bush and [a plant with similar name].

Habitat: in Woods on heavier soils beneath chalk hillsides, but in the north also grassland, usually on well-drained alkaline soils and downlands, old pastures and upland hay meadows. Sometimes in calcareous sand dunes. Only occasionally found on slightly acid moorlands.

Smells strongly sweet and slightly of vanilla, particularly at night. The white flowers are highly reflective, very conspicuous in moonlight. It is pollinated by moths, in particular the Silver-Y Moth and the Small Elephant Wawk-moth, setting seed in 70% to 90% of the capsules.


  Platanthera chlorantha  ⇐ Global Aspect ⇒ Orchidaceae  

Distribution
 family8Orchid family8Orchidaceae

 BSBI maps
genus8Platanthera
Platanthera
(Butterfly-Orchids)

GREATER BUTTERFLY-ORCHID

Platanthera chlorantha

(Formerly: Habenaria chlorantha) and Habenaria virescens)
Orchid Family [Orchidaceae]

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