Eucalyptus rudderi is a tree that typically grows to a height of and forms a
lignotuber. It has rough, fibrous or flaky grey bark on the trunk and branches. Young plants and
coppice regrowth have stems that are square in cross-section, and narrow lance-shaped, dull green leaves that are long and wide. Adult leaves are the same shade of green on both sides, lance-shaped, long and wide, tapering to a
petiole long. The flower buds are arranged on the ends of branchlets in groups of seven on a branched
peduncle long, the individual buds on
pedicels long. Mature buds are oval, about long and wide with a conical
operculum. Flowering occurs from March to April and the flowers are white. The fruit is a woody barrel-shaped or hemispherical
capsule long and wide with the valves near rim level. ==Taxonomy and naming==