Platanthera bifolia - Lesser Butterfly Orchid

Scientific Name: Platanthera bifolia – 'platanthera' is from the Greek 'platys' (= broad) and the Latin 'anthera' (= the pollen receptacles), refering to the widely spaced anthers on the closely related P. chlorantha. 'Bifolia' = from the Latin for 'two leaved', a reference to the two large basal leaves at ground level.

English Name: Lesser Butterfly Orchid.

French Name: Platanthère à deux feuilles (= Two-leaved Platanthera). Sometimes Double feuille (= 'Double Leaf'), Platanthère à fleurs blanches (= White flowered Platanthera) or Orchis à deux feuilles (= Two-leaved Orchid).

5 Key Characters:
  • anthers close-set and parallel.
  • prefers neutral to acid soil.
  • flowers white and very scented.
  • long (20-30mm) slender eperon (the 'tube' at the back of the flower), not thickened at the tip.
  • petals and sepals at the top of the flower quite upright and somewhat pointed, with a tendency to a graceful twist in the petals.
Lookalikes: Other Platanthera spp, especially Greater Butterfly Orchid P. chlorantha. They can be distinguished by the arrangement of the anthers (parallel v spread); length of eperon (long v very long); shape of eperon (tip not thickened v thickened tip); 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 (acid v. calcareous); arrangement of top petals and sepals (more upright and pointed, with a tendency to a graceful twist in the petals v rather broad and rounded). 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 semi-shade, in the Touraine it appears almost always on soil that is neutral to acid (unlike other regions of France); limestone, sand; wet long grassland, marshes, dry short grassland, heathland, woodland clearings, scrub, roadsides.

Flowering Period: May-June-July-August. Where the soil is more acid flowering tends to be later.

Status: Fairly common. Can be seen within 5km of Preuilly-sur-Claise. Quite evenly distributed in small, sparse colonies throughout the Touraine, Brenne and Sologne although rare or absent on calcareous soil.

Recorded by Loire Valley Nature:

No comments:

Post a Comment