This is a summary of an article appearing in theconversation on 30th September 2022 written by Darren Crane and Stuart Worboys
The lillypilly is a familiar Australian plant we often grow in our gardens. It actually makes up the largest genus of trees in the world and has a history more interesting than we might imagine!
Lillypillies evolved at some point during the breakup of Gondwanaland on the land mass incorporating Australia and New Guinea (the Sahul Shelf). That land mass collided with South-east Asia (the Sunda Shelf) about 17 million years ago and lillypillies migrated north. There are now around 1,200 lillypilly species in Africa, Asia, the Pacific and, of course, Australia. To track lillypillies’ journey, researchers used genomic information, which can help them build a family tree of species. They found that lillypillies didn’t make just one single journey from Australia but spread outwards in at least a dozen distinct waves. Each lineage successfully adapted to its new rainforest environment, making them now the largest global tree genus.
Lillypillies belong to the myrtle family (Myrtaceae) and the genus Syzygium, which contains five subgenera, including Acmena and Syzygium. Their beautiful, showy flowers attract a wide range of birds and insects but many species are also used for food (the locally grown riberry (Syzygium luehmannii) gives us a bush food berry and an Indonesian species produces cloves) and a source of antibacterial compounds.
While the spread of lillipillies is a great success story, they face many current threats globally along with other rainforest plants. Two of the most serious threats are habitat degradation and climate change. One coastal NSW species, the magenta lillypilly (Syzygium paniculatum) is threatened by development, while a Queensland species with a very restricted distribution (Syzygium fratris) is very vulnerable to climate change. All species, however, being in the Myrtaceae family, now have to cope with myrtle rust, a devastating disease that reached Australia in 2010.
Lillypillies play a major role in maintaining rainforest biodiversity and are important to Indigenous cultures. They clearly need to be protected!
Some management strategies we can use to protect lillypillies are here (https://theconversation.com/the-50-beautiful-australian-plants-at-greatest-risk-of-extinction-and-how-to-save-them-160362). We can also help preserve them ourselves by continuing to grow them in our gardens. You can find detailed information on a number of species in the Society’s plant database to help you grow and nurture them!