Observations on the ecology and conservation status of Haloragis exalata subsp. exalata (Haloragaceae) in southern New South Wales

Haloragis exalata F. Muell. subspecies exalata (family Haloragaceae), a perennial forb, is currently listed as Vulnerable, under both national and New South Wales threatened species conservation legislation. Very few herbarium records existed until recently. Recent discoveries of Haloragis exalata subsp. exalata in new sites on the NSW South Coast and Southern Tablelands prompted us to carry out surveys for the two varieties of the taxon, var. exalata and var. laevis. Our surveys in 2004– 2007 aimed to relocate historical collection sites and target areas of potentially suitable habitat in these areas. Our work has substantially increased the number of known localities for Haloragis exalata subsp. exalata var. exalata. It can be locally abundant. Ecologically it appears to function as a gap species whose populations are almost invariably found at sites where disturbance through temporary inundation, physical disturbance, or fire, has exposed bare earth with higher levels of light at ground level than would be present when the local vegetation community is intact. There are morphological differences between populations in disjunct areas. Haloragis exalata subsp. exalata var. laevis is much more restricted. As a result, the conservation status of Haloragis exalata subsp. exalata may need revision, considering that a) var. exalata is more widespread than previously known, but that b) there is only one known extant population of var. laevis, and that c) the population from Geehi area may be a distinct taxon