Alder tree (Species, Alnus sp.; Family, Betulaceae)
Alder tree and shrubs are deciduous and mostly native to north temperate locations with cool, moist soil. They are part of the Betulaceae family that also includes: birch, hornbeam, hop-hornbeam, and hazel trees. Alder trees, like birch trees, are used for landscaping and are commonly found in and around Canberra gardens, parks and streets.
Since alder trees are in the same family as birch trees they are very similar. Like birch tree pollen, alder tree pollen is derived from tightly bunched flowers, called catkins, that produce large amounts of pollen during August to October. Alder tree pollen is capable of causing hay fever and bronchial asthma.
Distribution of Alder tree (Atlas of Living Australia occurrence map)