The Lamington Ox Tongue Fern is characterised by fronds with a prominent very narrowly winged strip of 2 to 7 cm in length. The blade of the leaf is narrowly elliptic to lanceolate being 4–8 cm long and 5–9 mm wide. The blade is tapered at each end, semi-erect to pendent slightly sickle-shaped, leathery, dark green and shiny above, paler beneath; margins slightly irregular; apex broadly obtuse in sterile fronds, gradually tapering to a point and sub-obtuse in fertile fronds; venation obscure, with long narrow areoles. Spores are sparse and spreading for a short distance along the main veins being absent from the central band. The oblanceolate shape of the Lamington Ox Tongue Fern fronds, lacking lobes, and the arrangement of spore into discrete lines along the netted venation on the underside of fertile adult plants are distinctive and are unlikely to be readily confused with any other fern by an experienced observer who has seen a photograph or specimen of this plant.
Border Ranges Lined Fern, Lamington Ox Tongue Fern |
Antrophyum austroqueenslandicum
Status: Critically Endangered on the EPBC Act list
Government evidence of impact of climate change:
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Australian Government, Conservation Advice, Antrophyum austroqueenslandicum
Although the known population of the Lamington Ox Tongue Fern is within a conservation area covenanted in perpetuity with the Nature Conservation Trust of NSW and within the Mount Jerusalem National Park; illegal collection remains a potential threat (HSI 2016). 4.0 Climate change 4.1 Reduced Known Future Given the species highly specific microclimate rainfall and (constant high humidity and air movement with increased proximity to rainforest and or flowing water) severity and climate change is a potential threat to the duration of Lamington Ox Tongue Fern.
Climate change drought predictions indicate there will be continued increases in average temperature in all seasons; with more hot days and warm spells; the average winter and spring rainfall is projected to decrease (with increased intensity of extreme rainfall events) and longer and more extreme drought conditions as well as increased risk of fire in this species habitat (CSIRO 2020 Silcock Collingwood; in prep.).
The causes for the reduction are not clearly reversible or ceased; that is habitat disturbance; natural disturbances; invasion by weeds and changes in habitat suitability due to climate change.
In addition; climate change predictions indicate there will continue to be an increase in average temperature in all seasons; with more hot days and warm spells; the average winter and spring rainfall is projected to decrease (with increased intensity of extreme rainfall events) and longer and more extreme drought conditions as well as increased risk of fire in this species habitat (CSIRO 2020 Silcock Collingwood; in prep.).
The Tyalgum; Mount Jerusalem and Huonbrook Valley subpopulations are fragmented with a single event such as drought; flood or fire having the potential to affect all individuals of both subpopulations and potentially place this species at risk of extinction from a single event.
Weber pers comm.4th September 2020); more rarely up to 15 years; given the ferns seem to prefer growing on boulders in humid but not drought proof areas; and are clearly impacted by drought; though in ideal conditions it could be as short as 3 to 5 years (L.
The Tyalgum; Mount Jerusalem and Huonbrook Valley subpopulations are fragmented with a single event such as drought; flood or fire having the potential to affect all individuals of both subpopulations and potentially place this species at risk of extinction from a single event.
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