Nature conservation

Threatened species

Variable Midge Orchid - profile

Indicative distribution


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Key:
known
predicted
The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas. ( click here to see geographic restrictions). The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Genoplesium insigne
Conservation status in NSW: Critically Endangered
Commonwealth status: Critically Endangered
Gazetted date: 17 May 2015
Profile last updated: 26 Jul 2019

Description

A terrestrial orchid with a solitary cylindrical leaf that encloses the flowering stem. The leaf is 6 to 15 cm long, 0.15 cm wide, and dark green with a reddish base. The flowering stem is 9 to 18 cm tall, bearing 5 to 12 flowers in a moderately dense spike, 15-25 mm long. Flowers are dark purple and approximately 5 mm in diameter. The species was reclassified to Corunastylis insignis in Orchadian 13(10): 461 (2002). The species is currently listed by the Commonwealth as Corunastylis insignis.

Distribution

Recorded from four localities between Chain Valley Bay and Wyong in Wyong local government area.  A small population also occurs within Lake Macquarie LGA.

Habitat and ecology

  • Appears to be associated with PCT 1636 Scribbly Gum – Red Bloodwood – Angophora inopina (not always present) heathy woodland on lowlands of the Central Coast and variations containing Angophora costata (Smooth-barked Apple).
  • Recent and historic disturbance regimes (fire, clearing, routine slashing) appear to influence above ground emergence (i.e. leaf and flowers). Several known sites exhibit a removed/managed shrub layer and canopy, therefore shading and competition/biomass is likely to inhibit above ground emergence. However, a lack of disturbance is not considered an adequate justification to exclude the potential existance of the species, as the species can remain dormant underground for a number of years and has been known to emerge and swarm in dense and intact vegetation after fire.
  • Known locations/populations of plants exhibit dormancy for greater than four years (likely to persist underground for greater than four years). Therefore, absence in a given year may be a 'false absence' and the plants can re-emerge once conditions are favourable (e.g. rainfall in winter and appropriate disturbance).
  • Grows in patches of Themeda triandra (Kangaroo Grass), which can be ephemeral. Other associated species include, but are not limited to, Mirbelia speciosa, Ptilothrix deusta, Leptospermum trinervium and Leptospermum juniperinum in wet (seasonal) heath settings, Banksia spinulosa and Xanthorrhoea latifolia, and Xanthorrhoea media.
  • Other seasonal and cryptic species commonly associated with known populations include: Cryptostylis subulata, Cryptostylis erecta, Thelymitra ixiodes, Thelymitra pauciflora, Microtis spp., Burchadia umbellata, Tricoryne elatior, Thysanotus juncifolius.
  • Population numbers of flowering plants fluctuates between years due to dormancy. The number of individuals in the meta-population is therefore an estimate and likely to be around 50 plants - monitoring of the populations through the Saving our Species program is informing population size.
  • Flowering period is typically from September to October, but has been recorded flowering in mid to late November to early December. Note, this species is extremely difficult to locate even when in flower and cannot be definitively identified from leaf alone. Local climatic conditions appears to play a key role in flowering events, with rainfall possibly driving flowering. In drier periods, initial signs of above ground activity may emerge (e.g. leaf and spike), though flowers have been observed to wither in the absence of suitable conditions (e.g. soil moisture).

Regional distribution and habitat

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Threats

Recovery strategies

Activities to assist this species

Information sources

IBRA Bioregion IBRA Subregion Known or predicted Geographic restrictions region
Sydney BasinWyong Known None