24 July 2008

Esperance Bird Orchid - Pterostylis sp. 'Esperance'

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Esperance Bird Orchid - Pterostylis sp. 'Esperance'

A most interesting looking orchid with a large hairy labellum, and better still one of the most common and adaptable in acid soils around Esperance, although usually only found as a few scattered individuals. However, once you find one there are usually others spread within the habitat. It can be found from around Ephemeral swamps to sheltered summits of well vegetated acid dunes (often clumps of Banksia speciosa) and particularly those with a southerly aspect.

It is usually between 100-150 mm (4"- 6") in height, although can grow taller amongst other vegetation. The flowers are around 40 mm (11/2") in length, so quite a large flower and although green in color, the mustard yellow labellum usually gives it away. They also have a few stem leaves and a basal rosette. Flowering time is usually September and October.

Update 23/12/08
This orchid has been separated from Pterostylis turfosa in the publication 'Orchids of Western Australia' by Andrew Brown et.al. Apparently the labellum is more densely bearded in the Esperance Bird Orchid.