The Miena cider gum, Eucalyptus gunnii subsp. divaricata (Myrtaceae): a taxon in rapid decline

Abstract

The new combination Eucalyptus gunnii subsp. divaricata (McAulay & Brett) B.M.Potts comb. & stat. nov. is introduced for the Miena form of the Tasmanian cider gum Eucalyptus gunnii Hook.f., once described as a separate species, E. divaricata McAulay & Brett. This subspecies occurs on the Central Plateau of Tasmania, where it intergrades clinally with E. gunnii subsp. gunnii and E. archeri. Core populations of this subspecies are among the most frost-resistant of E. gunnii sens. lat., have juvenile foliage of interest for floriculture and have been exploited historically for their sweet sap. However, high mortality of trees in the last decade, coupled with only rare seedling recruitment and poor seed crops, is threatening the long-term survival of this taxon in the wild. E. gunnii subsp. divaricata qualifies as Endangered under Commonwealth and Tasmanian legislation.