Peristeranthus hillii (an orchid) - vulnerable species listing
The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list Peristeranthus hillii (F. Muell.) T. E. Hunt, an epiphytic orchid, as a VULNERABLE SPECIES on Schedule 2 of the Threatened Species Conservation Act. Listing of vulnerable species is provided for by Part 2 of the Act.
NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. Peristeranthus hillii (F. Muell.) T. E. Hunt is an endemic Australian orchid and has been described by Jones (1993) as follows:
"Epiphyte forming semi-pendulous clumps, the coarse stems to 30cm long and about 5mm thick, turning up near the apex. Leaves three to ten, to 25cm x 40mm, oblong, more or less pendulous, light green with numerous prominent veins, the tips unequally lobed, often twisted. Racemes to 25cm long, pendulous, bearing numerous, fragrant, downward-facing flowers, about 7mm across, which are pale green with numerous crimson spots. Perianth segments narrow, widely spreading, usually incurved near the tips. Dorsal sepal erect and incurved, lateral sepals divergent, incurved, petals obliquely erect, slightly incurved. Labellum about 2.5mm long, hinged; lateral lobes about 1.5mm x 1.5mm, triangular; spur about 1mm long, tapered, hollow. Lamina callus of a conical, erect structure about 1mm long."
2. Peristeranthus hillii is found in north eastern NSW, north from the Hastings River (Port Macquarie), and extends to north eastern Queensland, as far as the Bloomfield River. In subtropical regions, including NSW, the species is restricted to coastal and near-coastal environments, particularly remnants of littoral rainforest growing on aeolian sands and lowland subtropical rainforest on floodplains.
3. The species is currently known from 11 sites in NSW, most of which are small in area (
4. A further two historical subpopulations from Cape Byron and Ballina, areas now extensively developed, are believed to have gone extinct. Recent observations at one extant location near Port Macquarie suggest that the number of individuals has declined over the last decade.
5. The species' primary habitat includes Lowland Rainforest on Floodplain and Littoral Rainforest. Both Lowland Rainforest on Floodplain and Littoral Rainforest in the NSW North Coast, Sydney Basin and South East Corner Bioregions are listed as Endangered Ecological Communities on Part 3 of Schedule 1 of the Act. Both have undergone extensive clearing and degradation throughout their range due to widespread forest removal and intensive coastal development since European settlement. Remaining stands are small and isolated and are subject to the effects of stochastic events such as storm damage, canopy dieback due to salt and wind damage resulting from clearing or damage to stand margins, and wildfire. Such events can directly destroy epiphytes such as Peristeranthus hillii, or have a detrimental effect on the species by alteration of the microclimate due to loss of surrounding vegetation. Other threats to these stands include fragmentation resulting in loss of connectivity and possibly reduced genetic exchange between populations; weed invasion; and visitor disturbance. Furthermore, stands located outside conservation reserves may be at risk of clearing and development (Adam, 1987; Floyd, 1990).
6. Peristeranthus hillii is threatened by habitat destruction and fragmentation, environmental and demographic stochasticity due to its small population sizes, storm damage, canopy-dieback, wildfire and illegal collection (Bishop, 1996).
7. In view of above the Scientific Committee is of the opinion that Peristeranthus hillii (F. Muell.) T. E. Hunt is likely to become endangered in NSW unless the circumstances and factors threatening its survival or evolutionary development cease to operate.
Associate Professor Paul Adam
Chairperson
Scientific Committee
Proposed Gazettal date: 11/06/04
Exhibition period: 11/06/04 - 23/07/04
References:
Adam P (1987) New South Wales rainforests: the nomination for the World Heritage list. New South Wales NPWS, Sydney.
Bishop A (1996) Field guide to the orchids of New South Wales and Victoria. University of New South Wales Press, Sydney.
Floyd AG (1990) Australian rainforests in New South Wales. Surrey Beatty and Sons, Sydney.
Jones DL (1993) Native Orchids of Australia. Reed, Australia.