Thursday, April 30, 2009

Green Bollygum

Neolitsea australiensis
The fruits of green bollygums are early this year at Ravensbourne, beginning to ripen already. They are showy dark red, ripening to black, and look rather like giant versions of fruit of the closely related camphor laurel tree. They are highly nutritious and very attractive to birds, making this one of our best species for planting in bird-friendly gardens.
Only the female trees have the bird-attracting fruits, so it is worth planting a number of them, to be sure of a mix of the sexes
Bollygums are fast-growing small, slender trees, which like to grow in the understorey of dry rainforests. We have two local species. Green bollygum is happiest on red soil where it will get little or no frost. (Its cousin the white bollygum, Neolitsea dealbata, grows on a wider range of soils, and is hardier to both frost and drought. It can be distinguished from green bollygum by the hairiness of its young leaves.)
The virtue of understorey plants in gardens is that their roots co-exist happily with the roots of other trees, so they are good for planting under established trees or in shrubberies and rainforest-style gardens, where close planting is the go.

When new, green bollygum’s leaves are very distinctive ornamental purplish-green, and hang limply. As they mature, they become shiny green, with a pale greyish-white waxy bloom on their backs. Young plants have particularly large, showy leaves.

 This is a plant which likes fertile soil, and appreciates a good layer of organic mulch.

Green bollygum is one of the plants that is unable to germinate near its vigorous, introduced relative the camphor laurel tree. In an ideal world, we would be taking care that these invasive weeds are never allowed to escape into the shrinking remnants of the bollygum’s existing habitats, as they could cause its extinction. The hope that bollygums will continue to exist in the wild, a few hundred years from now, may be a vain one. Camphor laurels have been spreading in the bushland here ever since they were introduced as an ornamental plant more than a century ago. Though they spread more in our district than they have in coastal habitats, it may be inevitable that this single species will eventually take over from the eighteen or so of its laurel-family relatives which now grace our rainforest habitats.

Tuesday, April 21, 2009

Brisbane Lily

Proiphys cunninghamii
I showed you a photo of some of my lovely white Brisbane lilies last December. Their green bulbils have at last ripened to orange.
I find that few of the green bulbils actually make it to maturity, so am rather pleased with a crop of three.

Saturday, April 11, 2009

Bunyas in Flower

Araucaria bidwillii
Here are some of the male flowers which can be seen on Bunya trees around the district at the moment. When new, they are such a pretty shade of blue - and have the interesting characteristic of occurring on the lower branches only. The female flowers are higher up in the trees.
This suggests careful planning on the part of these canny plants. They don’t want to fertilise themselves, so this arrangement means that their pollen is more likely to get dispersed (by the wind) to the female flowers on other trees.

I don’t know how old this lovely avenue is, but think it quite likely that the person who planted the original seeds is still living. It’s possible to create something like this in your lifetime, and leave a beautiful legacy that can last for hundreds of years.

Friday, April 10, 2009

More about “Ruby” Saltbush.

Enchylaena tomentosa


Here’s a photo of the plant I mentioned in last month’s blog. As I said, it comes in two common forms - the ruby-fruited groundcover shown in that blog, and the upright form with orange fruits which I photographed at lake Broadwater today.

Saturday, April 4, 2009

Fairies’ Purses

Bursaria spinosa
This under-appreciated shrub is one of Australia’s most widespread native plants, growing from Queensland to Tasmania and South Australia.
We usually see it as a dense, prickly roadside bush, which provides good shelter and nesting sites for small birds, and becomes smothered in fragrant, white flowers from Christmas-time onwards. In some areas it is known as “Christmas bush”. It also goes by the names of “native blackthorn” or “prickly pine” - but most people simply call it “Bursaria”.
There are still some flowers about, but most of the bushes are now covered in tiny brown seed-capsules, which delight children as they contain little black seeds, like coins in a purse.
The plants we see may have roots which are much older than the visible parts of the plant, as this is one which regrows after bushfires.
Left alone, those plants have the capacity to become 10 m high trees, which outgrow their tendency to be prickly - but they get there very slowly. The flowers are very appealing to butterflies, and a favourite with native bees.
They would do very well in gardens - probably looking prettier than the tough old cattle-munched specimen at left.
Bursarias are known to have a lifespan of at least 60 years, but it is probably much longer. Ideally gardeners would plant them between faster-growing, shorter-lived garden species.
These are trouble-free plants, hardy to frosts and droughts.