Eucalyptus × missilis is a mallee that typically grows to a height of and forms a
lignotuber. It has smooth dull grey bark. Adult leaves are egg-shaped to lance-shaped, the same shade of glossy green on both sides, long and wide on a
petiole long. The flower buds are arranged in leaf axils in groups of between seven and fifteen on a thick, unbranched
peduncle long, the individual buds
sessile or on
pedicels up to long. Mature buds are spindle-shaped, long and wide with a blunt, conical
operculum. The flowers are pale yellow and the fruit is a woody, cylindrical to cup-shaped
capsule, long and wide with the valves at rim level. The characteristics of this mallee are intermediate between those of
E. cornuta and
E. angulosa but the authors,
Ian Brooker and
Stephen Hopper consider "that the morphological uniformity of mature individuals within and between all populations justifies taxonomic recognition of the species." It is usually found growing with both parent species. ==Taxonomy and naming==