- Remote sensing of pattern, texture and colour using high resolution ADS40 aerial photograph imagery identified 30 known and potential polygons of the listed Vulnerable mallee eucalypt Eucalyptus dissita (Myrtaceae) in Gibraltar Range National Park in the NSW New England Tablelands Bioregion. Targeted field surveys confirmed Eucalyptus dissita in 14 mapped polygons, covering a mapped extent of 7.6 hectares, with an estimated population of 2400–4600 mallee/ tree stems, including two new populations in remote locations along tributaries of Dandahra Creek and proposed as newly named management sites (Dragonfly Swamp and Valley of the Mallees) under the NSW Saving our Species Program. Populations of Eucalyptus dissita were burnt in a November 2014 hazard reduction burn, and again in the extensive December 2019 wildfire. After the 2014 fire, basal resprouting was observed and minimal mortality of pre-fire plants recorded, but no seedling recruitment observed. In May 2019, 4.5 years post-fire, five of 20 tagged individuals at Surveyors Creek were forming floral buds but are likely to require another year to seed production. All of these individuals were burnt again in the December 2019 fire. Full floristic data analysis using hierarchical agglomerative clustering revealed that Eucalyptus dissita forms a quantitatively distinct vegetation assemblage that groups with the vegetation of swamps and rocky riparian areas, adjoining granite hills.