Botanic Gardens Trust, Sydney, Australia

Elusive carnivorous plants finally uncovered in north

Recent fieldwork across Australia by garden’s botanist Dr. Richard Jobson has lead to collections of several new, and two rare species for inclusion in an evolutionary study of the bladderwort genus Utricularia.

These aquatic carnivorous plants occupy nutrient deficient habitats ranging from coastal heathlands and swamps to desert mound springs across all states of Australia and most regions of the world.

Possessing a beautiful array of floral forms, these plants capture tiny prey organisms in intricate leaf structures called suction-bladders, that are positioned in water or wet soil. Sensitive to nutrient and prey regime shifts, bladderworts can provide insight into the health of their usually finite freshwater habitats.

Although Dr. Jobson’s earlier PhD work on bladderworts involved a broad study of many of the 220 species from across the world, most of the 64 Australian species remained unstudied.

A research grant from the Australian Biological Resources Study ($33,000 over three years), has allowed Dr. Jobson to investigate the relationships between the Australian species, with particular focus on species complexes with wide distribution and high levels of morphological variability.

Fieldwork has taken Dr. Jobson to most corners of Australia in search of known and unknown Utricularia species. At the National Herbarium of NSW he is also responsible for the scientific curation of several other plant families, such as grasses, and utilises field trips to broaden specimen collections from poorly explored regions.

Two recent trips to far north Queensland involved collections of Utricularia species from mound spring habitats at Peery Lake in far north west of NSW, and on through to Artesian springs that are scattered across arid regions of western Queensland.

In search of Utricularia sp. ‘Mt Tozer', Lockhart River settlement was the most northerly site for the first trip. The second trip was focused on recollection U. albiflora and U. terrae-reginae, two rare species located in isolated sand dune swamps north of Cooktown. 

Utricularia  albiflora was first collected by Banks and Solander in 1770, and apart from a single collection in 1982, has until now remained elusive. For a decade Dr. Jobson has lead numerous expeditions in search of this mysterious plant, and was not only rewarded with its presence, but also that of a new species U. sp. ‘Cooktown’, found growing nearby.

In addition to the discovery of rare and new species of Utricularia, the expeditions turned up a new species of Isotoma (Campanulaceae) in northern NSW, and a new Australian record for the Asian Mimulus orbicularis (Phrymaceae) on the west coast of Cape York Peninsula. Formal investigations of their taxonomic status are currently underway.

Dr Jobson’s work will provide necessary data for production of a revision of the Australian species of Utricularia for inclusion in the Flora of Australia. This will contribute to our understanding of Australia’s biodiversity, and aid in the conservation and management of environmentally sensitive habitats.


 

Fig1_cooling-down-at-Mt-Tozer
Fig 1. Cooling off during searches near Mt Tozer. Lockhart River settlement Qld.

Fig2_sort-specimens-at-Laura-Qld
Fig 2. Sorting and pressing specimens at campsite near Laura Qld.

Fig3_washedout-river-crossing---end-of-road
Fig. 3. Wet season washout; the track to Gamboola soda springs come to an abrupt end.

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Fig.4. Utricularia sp. ‘Mt Tozer’ discovered near Lockhart River settlement.

Fig5_Elusive-Utricularia-albiflora
Fig. 5. The elusive Utricularia albiflora is finally found.

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Fig. 6. New species Utricularia sp. ‘Cooktown’ is discovered nearby.

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Fig. 7. Another rare species; Utricularia terrae-reginae near Musgrave Qld.

Photos: Richard Jobson and Wayne Cherry.