Neither palm nor lily
The commonly grown Palm Lily, Cordyline australis, is, somewhat surprisingly perhaps given its species name (although austral just means southern) from New Zealand. We also call it the Cabbage Tree, not the Cabbage Tree Palm, which refers to Livistona australis, a true palm and truly from Australia.
The species illustrated here is Cordyline petiolaris, growing in the Australian Garden at Cranbourne Gardens. This Broad-leaved Palm Lily is from coastal and near-coastal parts of northern New South Wales and southern Queensland.
All up there are about 20 species of Cordyline eight from Australia. There are many in cultivation, including some brightly coloured cultivars, and they are tough plants as long as you don't have frosts. For more on how to grow them and the horticultural forms, check out the International Cordyline Society website.
But what kind of plant is this Palm Lily? Well, it's neither a palm nor a lily (or a cabbage for that matter). It sits in the family Asparagaceae, with things like ... yes, asparagus. To be fair, most things in this family were once included in the Liliaceae, which is where true lilies reside.
The Palm Lily's cluster around the Mat Rush Lomandra and you sometimes see it put in the family Lomandraceae. Or Agavaceae (with Agave). Or Asteliaceae (with the Pineapple Lily, Astelia). Or Laxmanniaceae (with the Wire Lily, Laxmannia).
Or Dracaenaceae, with Dracaena, including the Dragon Blood Tree and other common ornamentals. Sometimes Dracaena and Cordyline get confused but scratch below the surface (of the soil) and you can tell them apart - Dracaeana has orange roots, Cordyline white.
Anyways, today the DNA tells us Cordyline is best included in Asparagaceae. This giant asparagus might look like a palm from a distance but close up you'll see it doesn't have the single crown of leaves and the compound (feathery or fan-shaped) leaves pleated down the middle when young. And flowers, molecules and other bits and pieces are different.
In its native rainforest or wet eucalypt forest the Broad-leaved Palm Lily will reach five metres tall, but in most gardens it tends to settle at something like two metres; I suspect those at Cranbourne Gardens will seek greater heights, if we can offer them a little protection.
As to those gorgeously red berries that look like they'd make a fine jam or pie. I gather the giant moas in New Zealand ate the fruit of Cordyline australis, as do various non-extinct birds today. The fruits of Cordyline petiolaris are described as 'edible' and also 'eaten' but the interweb isn't awash with recipes for humans (or birds). More usually it's the leaves and roots of Cordyline that are eaten.