Saturday, July 14, 2012

Pterostylis curta

Pterostylis curta - Blunt Greenhood

Family:  Orchidaceae

Common name: Blunt Greenhood

Flowers: A single large erect flower 3.5cm long, green and white with brown shading towards the apex. The labellum (tongue) is long and twisted to one side. This twist is an identifying feature of Pterostylis curta. Flowering period from Aug to Oct. [Note: anomalies can occur in the plant world, and a Pterostylis curta plant that I photographed in the Pilliga had two flowers rather than the specified single flower.]

Leaves and stem: A central stem to 30cm tall emerges from a basal rosette of 3 to 6 fleshy green, stalked leaves, up to 10cm by 3cm, often with wavy margin.

Habit: This terrestrial orchid often grows in extensive colonies and flowers freely. I was told about a colony of greenhood orchids in a particular place in the Pilliga and went to investigate, finding most had already perished with only a few remaining flowering. A colony of flowering Pterostylis curta can be quite spectacular.

Habitat: I found the Blunt Greenhoods growing in a damp grassy shady area in the Pilliga. All the images I have here indicate the lush growth of grasses and  herbs, and the usual habitat of Pterostylis curta is recorded as moist sheltered areas in open forest, woodland and heathy forest. It also occurs in Qld, Vic, Tas, SA, and ACT.

[Note: Pterostlis curta is not included in Leo Butler's April 2009 list of plants in the Pilliga Forests.]
Leaves of Pterostylis curta - notice the stalks

Stem with stem-hugging sheaths

2 flowers on the one plant is unusual

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