Cluster Mallee

Eucalyptus obesa, the cluster mallee, is a rare multi-stemmed shrubby eucalyptus in the family Myrtaceae endemic to a restricted area of the Wheatbelt region of Western Australia. Like many mallee eucalyptus species, it grows as a lignotuberous shrub 2–5 meters in height, with multiple stems arising from a swollen underground rootstock called a lignotuber, which allows the plant to regenerate vigorously after fire or drought. Cluster mallee occurs on seasonally waterlogged clay soils and the margins of salt lakes, habitats that are naturally limiting but which have also been severely altered by agriculture in the Western Australian grain belt. The species is classified as Near Threatened by the IUCN, reflecting its limited distribution, small total population, and ongoing habitat degradation from land clearing, altered drainage patterns, and secondary salinisation associated with agricultural activity. Its deeply dissected range consists of isolated populations among a heavily transformed agricultural landscape. The species produces cream-coloured flowers typical of eucalypts in its taxonomic grouping and provides food resources for nectar-feeding birds and insects in the arid to semi-arid scrub communities it inhabits. Conservation of remaining populations depends on protection from further land clearing and management of invasive pasture grasses.