Alder or "brown", which is also a root for the English words "elk" and another tree: "elm", a tree distantly related to the alders. With a few exceptions, alders are deciduous, and the leaves are alternate, simple, and serrated. The flowers are catkins with elongate male catkins on the same plant as shorter female catkins, often before leaves appear; they are mainly wind-pollinated, but also visited by bees to a small extent. These trees differ from the birches ("Betula", another genus in the family) in that the female catkins are woody and do not disintegrate at maturity, opening to release the
Eucalyptus rigidula Eucalyptus rigidula Eucalyptus rigidula, commonly known as stiff-leaved mallee, is a mallee that is native to Western Australia. The mallee typically grows to a height of . The bark of the tree is smooth and white-grey brown in colour and peels in ribbony strips at the base. It blooms between December and April producing inflorescences with white flowers. The bark is smooth and powdery with no pith of bark glands. The disjunct, glossy, green or yellow-green adult leaves have a lanceolate to broad lanceolate shaped blade that is basally tapered. The thick concolorous blade is in length and wide. The