Thursday, April 30, 2009

Green Bollygum

Neolitsea australiensis
Family: LAURACEAE
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
Family: AMARYLLIDACEAE
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
Family: ARAUCARIACEAE
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

Family: CHENOPODIACEAE

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
Family: PITTOSPORACEAE
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.

Thursday, March 26, 2009

Ruby Saltbush

Enchylaena tomentosa
Family: CHENOPODIACEAE
Saltbushes are such useful plants, and these family members are no exception.
Like most saltbushes, they are drought and frost hardy. They can grow in nutritionally poor soils, and in soils damaged by salinisation.
They have fruits which can be eaten raw. They are quite tasty, sweet, and rich in Vitamin C. Eat them straight from the bush, or use them as a pretty garnish for rice dishes, meusli, or salads.
The plant has salty leaves which are valued as high quality stock fodder, but they can also be eaten by people, providing a good source of Vitamins C and E. There are better tasting vegetables, but in times of vegetable scarcity saltbush leaves have been valued for their ability to stave off scurvy. The quantity of salt they contain varies, depending on the amount in the soil where they grow. They need to be cooked, and boiling them briefly also removes much of the salt.
Nowadays we would throw this salty water away, but early settlers and explorers needed a source of salt, both for their health, and for preserving meat. The salt from saltbushes was valued!
In good garden soil, given a bit of care from a gardener (including some pruning), they can be beautiful plants. They have blue-grey leaves, and bright fruits for a period of many months in summer and autumn. There are, broadly speaking, two local forms; the one with ruby-red fruits, which tends to be a dense ground cover, about 1m across and 25cm high; and an orange-fruited form, which more upright and has orange fruits. However fruit colour varies considerably within our region, and a selection of these plants can provide a multicoloured show.
All saltbushes are fire-retardant. Where fire is a possible threat to homes, saltbushes could be a better choice for a ground-cover in the garden than the popular, but flammable, wood-chip mulch.

Thursday, March 19, 2009

Golden Hollywood

a green fire-screen?
Auranticarpa rhombifolia (Pittosporum rhombifolium)
Family: PITTOSPORACEAE
These little trees are looking magnificent all over town at the moment. As one of the few local natives that have been planted as street trees in Toowoomba, they justify the faith of those who made the decision.
Street trees have a very tough life, so anything that can look good in those circumstances is definitely a winner as a garden plant.
Hollywoods are fast-growing trees with a tall, narrow growth habit. While they can be grown as nice little shade trees, their dense, dark green foliage reaches almost to ground level if they are left untrimmed, making them wonderful tall screens for a space only a 3-4 metres wide.
For a good privacy screen, plant at 2m apart for a good screen, and tip-prune when young for extra bushiness.)
Their roots will seek out water, so they should be kept well away from underground pipes.
They flower profusely in spring, attracting insects of all kinds (and the nesting birds, no matter what their normal diet, make use of the extra protein that this insect feast provides, at this busy time).
The bright fruits ripen after Christmas, and can last right through till next spring, opening to reveal the black fruits which birds also love.
They are drought resistant and hardy to light frosts. Their favourite soils are the red and black basalt soils.
And will they save your house from burning down?
Well, perhaps not in a fire such as we’ve seen recently in Victoria - so don’t stay at home when you ought to be evacuating!
However, they are hard to set alight, and do make a good spark-catching screen, so would be a very good choice of plant in a fire-prone area. They are certainly a much better plant, all round, than the highly flammable introduced cypresses, which are popular as screens in this district.