A sharp-eyed Sydney schoolboy last week discovered a plant at Launceston's Cataract Gorge that caused a ripple of excitement in the Tasmanian botanical community.
Trevallyn field botanist Roy Skabo said that Boaz Ng's interest in carnivorous plants led him to examine a small pond during a family walk near the causeway at the First Basin.
''He noticed some yellow flowers poking above the surface of the water and correctly identified them as Utricularia australis , otherwise known as yellow fairy's apron or yellow bladderwort,'' Mr Skabo said.
Unaware of the significance of his sighting Boaz posted his observation on an internet forum dedicated to carnivorous plants.
The item was brought to the attention of botanists at the Tasmanian Herbarium.
Mr Skabo said that the species, listed as ''rare'' on the Tasmanian Threatened Species List, had never before been seen flowering in Tasmania and only rarely in other parts of Australia and the Herbarium asked him to confirm that the plant was an Utricularia australis , rather than a similar-looking non-native.
Tests confirmed the discovery.
Mr Skabo said that the Utricularia australis spent its life underwater, except when it flowered and the flowers were thrust above the surface.
It had small bladders, about two millimetres across, which trapped its food source, tiny invertebrates, Mr Skabo said.