Syzygium

Two species of lilly pilly or brush cherry grow on our site. Their seedlings are very similar.

This one is probably S. smithii, the widespread lilly pilly that used to be known as Acmena smithii.

Much less widespread, but often seen in the Ourimbah Creek valley, is the magenta lilly pilly, Syzygium paniculatum.

Note the opposite leaves that resemble those of privet. But note also the deep colour of the leaves and the total absence of seed leaves (cotyledons). In lilly pillys, these remain underground.

Another diagnostic is that, when a privet leaf is torn, the upper and lower surfaces of the leaves come apart. Lilly pilly leaves give a straight tear.

More from the web:

Fruits of common lilly pilly, Syzygium smithii

Fruits of magenta lilly pilly, Syzygium paniculatum

As the seedling lilly pilly gets older, the glossy new leaves have a reddish colour as they expand, as on the twig shown below.