Genoplesium superbum - endangered species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list Genoplesium superbum D. L. Jones, a midge orchid, as an ENDANGERED SPECIES in Part 1 of Schedule 1 of the Threatened Species Conservation Act. Listing of Endangered Species is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Genoplesium superbum D. L. Jones is an endemic Australian orchid that has been described by Jones (1993) as follows: "Terrestrial herb 17-23 cm high. Inflorescence not crowded, 2.5-6 cm long, 4-15- flowered. Flowers c. 12 mm across, dark pinkish purple. Dorsal sepal ovate, c. 5.5 mm long, c. 3 mm wide, striped, margins ciliate. Lateral sepals linear to lanceolate, c. 10 mm long, c. 1.3 mm wide, slightly gibbous at the base, widely divergent. Petals ovate to lanceolate, c. 5 mm long, c. 1.8 mm wide, striped, long-acuminate, margins ciliate. Labellum linear to obovate, c. 7.5 mm long, c. 3 mm wide, margins with numerous, coarse, pinkish mauve cilia c. 2 mm long; callus narrow-ovate, extending about half way to the labellum apex. Flowers Dec-Mar."

2. Genoplesium superbum is restricted to the southern tablelands of NSW where it has been recorded from 2 locations near Nerriga, c. 20 km apart. The species occurs predominantly in wet heathland on shallow soils above a sandstone cap but has also been found in open woodland interspersed with heath. Some plants fall within the boundary of Morton National Park.

3. The population fluctuates from year to year and is currently estimated to contain fewer than 150 individuals (K. J. McDougall, pers. comm.).

4. Genoplesium superbum is threatened by environmental and demographic stochasticity due to its small population size and limited distribution. The larger of the two populations is threatened by vehicular damage, habitat degradation and illegal collection associated with its proximity to roadsides. A proposed road realignment is likely to destroy some individuals and to increase the susceptibility of others.

5. In view of the above, the Scientific Committee is of the opinion that Genoplesium superbum D. L. Jones is likely to become extinct in nature in NSW unless the circumstances and factors threatening its survival cease to operate.

Dr Lesley Hughes
Chairperson
Scientific Committee

Proposed Gazettal date: 25/11/05
Exhibition period: 25/11/05 - 20/01/06

References 

Jones DL (1993) Genoplesium. In 'Flora of New South Wales. Volume 4.'  (Ed. GJ Harden) pp. 163-170. (New South Wales University Press: Kensington).