Acmena smithii (Syzygium smithii)
This is one of our showiest local native trees. Found in the dry rainforests along the range, it looks spectacular at this time of year when it is laden with purplish pink fruits.
In garden situations, it becomes a medium sized tree (8-10 metres) though it can grow much larger in its native rainforest. It has dense foliage which (unless trimmed) extends to the ground, making it a good screen plant.
For this purpose it can be left to grow naturally, or trimmed to make a large, quick-growing hedge, with flushes of new red leaves stimulated by trimming. In either case, it is a very attractive garden plant.
It has been claimed that it resists frosts to to -7°C (or more). I have some doubts about the frost hardiness of small specimens, and would want to be protecting them in winter if harsh frosts are expected, until they were at least a metre high. This only takes only a year or two.
Acmena smithii is the drought hardiest of Australia's lillypillies.
Acmena or Syzygium?
Botanists have not come to an agreement about the name of this plant. All our lillypillies, of both Acmena and Syzygium species, were once grouped together under the name "Eugenia". Then in the 1930s they were split off from that genus and given their new names. This left only one Australian Eugenia species (and some 1000 overseas ones) behind.
Recently, there has been a move to put Acmena back together with Syzygium, which would give this plant the name "Syzygium smithii". Not everyone agrees, however. Botanists often disagree about whether similar plants are different enough to warrant being split up under two or more names, or whether their similarities justify lumping them together. In this case, we have lumpers in some states (and federally), who now use Syzygium smithii, and splitters sticking to their guns and "Acmena smithii" in Queensland and New South Wales.
We amateurs can certainly see clear differences between the two genera, so find the split convenient.
The fruit of Acmena has a neat circular cup at the apex of the fruit (the end opposite the stalk).
Here it is (above) on Acmena smithii...
...and on Acmena ingens, our two local Acmena species.
Syzygium fruit has this cup obscured by little fleshy claws - actually the remnants of the flower calyx.
Here they are (above) on Syzygium paniculatum, a species from the Sydney area growing in my garden...
... on Syzygium australe, photographed in the Bunya Mountains,
and somewhat less obviously on these Syzygium crebrinerve, from Goomburra.
The seeds are different, too.
The flesh clings very firmly to the seeds of Acmena species (above), and is hard to get off without damaging the rather soft seed. (Fortunately, for those who like to "flesh" seeds before planting them, Acmena smithii doesn't need this treatment, and grows well when planted which the fruit whole.)
Syzygium seeds sit quite loosely in the crisp white flesh, and are easy to pick out. Above is Syzygium australe...
...and this is Syzygium paniculatum.
A third rather similar fruit is that of the satinwood (above), Vitex lignum-vitae. It is sometimes mistaken for a lillypilly, but is easy to distinguish because there's nothing special about the apex of the fruit. Notice also that the white flesh discolours very quickly, like that of an apple.
Acmena and Syzygium can be distinguished from each other by their flowers, too.
Syzygium species (above) have large, fluffy flowers. May Gibbs used them as the inspiration for the delightful Miss Lilly Pilly, the famous movie star who meets Snugglepot and Cuddlepie.
Acmena flowers are rather boring by comparison.