Platanthera chlorantha - Greater Butterfly Orchid

Scientific Name: Platanthera chlorantha – 'platanthera' is from the Greek 'platys' (= broad) and the Latin 'anthera' (= the pollen receptacles), refering to the widely spaced anthers in this species. 'Chlorantha' = from the Greek for 'green flower'.

English Name: Greater Butterfly Orchid

French Name: Platanthère verte (= 'Green Platanthera') or Orchis verdâtre (= "greenish orchid").

5 Key Characters:
  • flowers white or greenish white, with little scent
  • very long (20-45mm) eperon (the 'tube' that sticks out the back of the flower), which is thickened towards the tip
  • anthers widely separated and sloping away from each other so that the tips are closer than the bases, forming an inverted 'V'.
  • preference for base-rich soils (chalk, calcareous, limestone)
  • greenish downward pointing tongue-shaped labellum (bottom petal)
Lookalikes: Other Platanthera spp, especially Lesser Butterfly Orchid P. bifolia. They can be distinguished by the arrangement of the anthers (spread v parallel); length of eperon (very long v long); shape of eperon (thickened tip v tip not thickened); P. chlorantha (May) tends to start its flowering season earlier than P. bifolia (June), although the end of their season overlaps into August; soil preference (chalk v acid); arrangement of top petals and sepals (rather broad and rounded v more upright and pointed, with a tendency to a graceful twist in the petals). P. chlorantha is almost ubiquitious in the area, and will probably be the one you encounter first and most frequently. Once you have seen both species you should have no trouble distinguishing them.

Habitat: Full sun to full shade on base-rich (calcareous) soils; dry short grassland, wet long grassland, marshes, woodland clearings, mixed forests, roadsides, heathland, forest rides, scrub. Primarily lime loving, but can be found in almost any soil type in fact, including clay. It rapidly colonises roadside and track banks.

Flowering Period: May-June-July-August.

Status: Common everywhere (in fact, the commonest orchid in Indre-et-Loire, where it is ubiquitious, and in the Sologne). Can be seen within 5km of Preuilly-sur-Claise.

Photographed by Loire Valley Nature:

Photographs are numbered from left to right and top to bottom. 1 still in bud, April, on a woodland track on a limestone ridge near Preuilly-sur-Claise. 2 a single flower, on its side with the labellum to the right, and the very long eperon to the left. The eperon is a nectar reservoir and the level of liquid can clearly be seen. Obviously only very long tongued creatures can access this nectar - in this case moths who are attracted to the plant first by its subtle evening scent and then encouraged by the sweet reward in the spur to push their heads into the flower and pollinate it.

The widely separated anthers in an inverted 'V' are easy to see in the centre of the flower.
A fully out flower spike.

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