How plants or animal species are grouped together
Similar plants or animals are grouped together. Those most similar are included in the same genus – e.g. the genus Eucalyptus groups the eucalypts or gum trees together. Each species of eucalypt (Eucalyptus) has a species name. e.g. Marri has the species name Eucalyptus calophylla, Karri has the species name Eucalyptus diversifolia and Jarrah the species name Eucalyptus marginata.
Similar genera (plural of genus) are grouped together into Families. For example, the genus Eucalyptus is grouped under the Family Myrtaceae together with genera such as Melaleuca, Kunzea, Verticordia and Agonis (e.g. the Peppermint Tree, Agonis flexuosa). They all have open-cup like disks to their flowers, a pungent aroma when crushing their leaves, often no petals or very few, and lots of stamens.
It is the same for animals. However, for large groups such as insects, it is often easier to start with the Order an insect is within. An Order (often ends in ‘optera’) includes many different Families. e.g. the Order Hymenoptera includes the families for bees, wasps and ants; Coleoptera the beetles and weevils; Hymenoptera the True Bugs; Lepidoptera the butterflies, skippers and moths.