NSW National Parks and Wildlife Service, September 2002
ISBN 0 731 36905 X
The Illawarra Greenhood Orchid (Pterostylis gibbosa) is a perennial terrestrial orchid. The tuberoid forms a flat rosette of leaves up to approximately 100 mm in diameter and the plant develops a flower spike that grows to 45 cm tall.
P. gibbosa is currently known from five locations: Milbrodale in the Hunter Valley, Yallah (2 sites) and Albion Park in the Illawarra and Nowra in the Shoalhaven. The species occurs among grasses in sclerophyll forest. The total known population size of P. gibbosa is approximately 4,500 plants although this is likely to be higher given the extent of the Milbrodale and Worrigee Nature Reserve populations which have not yet been fully assessed.
This Recovery Plan is a revision of the plan prepared for the Australian Nature Conservation Agency (ANCA (now Environment Australia)) in 1994. The majority of actions in the ANCA plan have been implemented including surveys on the Cumberland Plain and Illawarra regions, liaison with land managers, monitoring permanent quadrats for survivorship, flowering, capsule and seed production, and investigation of the response of P. gibbosa to fire.
This Plan describes our current understanding of P. gibbosa, reports on the implementation of the 1994 Plan and outlines the recovery program for this species for the next 5 years.