Eucalyptus calidissima (Myrtaceae), a new ironbark species from the Hunter Valley of New South Wales, Australia

Eucalyptus calidissima (Myrtaceae), a new and highly restricted ironbark species from the Hunter Valley of New South Wales is described and illustrated. The new species had previously been included in E. nubilis Maiden & Blakely (syn. Eucalyptus nubila L.A.S.Johnson, orth. var.), but differs in the ribbed hypanthia, hemispherical to bluntly-conical calyptra which are shorter than the hypanthia, and the slightly larger, globular to obconical ribbed fruit. At present, E. calidissima is known only from a single population occurring across c. 200 ha and is considered rare, but it is not under immediate threat. Amendments to relevant sections of the New South Wales and Australian identification keys are provided