The concolorous, glossy, green adult leaves are erect and alternately arranged.

[3][4] Eucalyptus pachyloma was first formally described by the botanist George Bentham in 1867 in Flora Australiensis.

[3] This species is part of the Eucalyptus subgenus series Diversiformae, a group of mallees that all have adult leaves held erect, buds with a single unscarred operculum and pyramidal seeds.

[3] Kalgan Plains mallee is found on sandplains and foothills growing in sandy soils in the southern Wheatbelt and Great Southern regions of Western Australia extending from around Pingelly in the north through to Albany in the south.

[2] This eucalypt is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.