Thursday, December 31, 2009

Brush Hovea

Hovea longipes
Famiily: FABACEAE
I have been trying to catch this plant in flower for ages, and am surprised to have found it (at Irongate Nature Conservation Reserve) at this time of year.
Most Hoveas flower, magnificently, in late winter. This one is said to flower from March to September, though I have not actually seen it myself.
I now wonder whether it is a very flexible opportunist, able to take advantage of rain, whenever it occurs, to try for a successful crop of seeds - as do so many of the plants of the inland. Perhaps the rather modest number of flowers was also normal.
I would love to grow this plant. It is regarded as being so different from other hoveas that some botanists would like to see it reclassified under a new name. The flowers are blue, rather than the usual hovea purple, and the seedpods are a different shape.
It is a particularly attractive plant, even when not flowering - a large, rounded shrub, between 2 and 3 metres tall, and with a more substantial trunk than we usually expect in a hovea. Cattle pruned examples suggest that in a garden it could be persuaded with the secateurs to become a dense shrub. I suspect it of being longer-lived than other hoveas.

Native Daffodil

Calostemma luteum
Family: AMARYLLIDACEAE
The native daffodils began to come into flower just before Christmas. Unlike the introduced bulbs, all our local native bulbs flower in summer rather than in spring.
These plants are daffodil-yellow, but in form they are more like scentless jonquils. It’s something of a puzzle as to why they are not grown more often in Australian gardens, as they are very attractive plants.
Not all the flowers open at once, so you don’t get a good flower for vase use, as you do with jonquils - you do get a longer flowering time per head. For a good display in the garden, quite a few bulbs are needed.
The flowers are followed by shiny green bulbils, which drop off and germinate on the soil surface if they find a damp and shady niche. Otherwise, they need a little help from a friend. In two years, they develop large bulbs which pull themselves down about 20cm under the soil, and then proceed to flower for many years, dying down every winter, and reappearing in early summer.
They are only moderately drought hardy. Young plants need quite frequent watering in their first year of life. Mature bulbs are hardier, but for best results they need a good soaking in November, and another one or two as the flowers die down and the leaves feed their nutrients back into the bulbs.

(There is also a pink Calostemma, which grows naturally in western NSW, north-western Victoria, and South Australia. It is sometimes classified as a variety of C. luteum, and sometimes as a separate species, C. purpureum. Its flowers don’t open as widely as those of our local yellow one, but it’s a pretty thing nonetheless, and a more drought-hardy plant than our local.)

Thursday, December 10, 2009

Weeping Bottlebrush

Callistemon viminalis (Melaleuca viminalis)
Family: MYRTACEAE
This widespread Australian native is one of our only two locally indigenous Callistemon species. It has a graceful shape and long flowering season, and is much used in local gardens and streets. As with all callistemons, its flowers attract honeyeating birds, and butterflies.
The natural habitat of these small trees is in watercourses, on all kinds of soil. They would once have been very common in all along the creeklines of the district, including those in inner-city Toowoomba, where they would have grown with black tea-trees (Melaleuca bracteata), river she-oaks (Casuarina cunninghamiana), and an assortment of rainforest trees, shrubs, and vines.

We still see many of them in creeks along the range, but they have been largely cleared from the red and black soils west of it.

The early white settlers gave particular attention to clearing the vegetation in our creek-beds. In the early days, it was because scrub-covered watercourses provided cover where aborigines could hide, and provided them with routes along which they could travel inconspicuously, and from which occasional attacks on white settlers were launched.
Later, it was done because of a belief that vegetation in creeks impeded the water flow, making floods worse.
What a pity that this ruthless clearing drove our local platypuses to extinction!
Early attempts at revegetation, once the value of trees in preventing erosion was recognised, was done with willows, because of their quick growth as well as the widely held belief that they were more beautiful than any native plant. Unfortunately, willows exclude low-growing vegetation under their canopies so effectively that the soil under them is poorly defended from scouring by floods.
Modern revegetation efforts in creeks use natives, including this species.
Despite their natural preference for a creek habitat, weeping bottlebrushes have proven to be very hardy trees in situations where they can be quite challenged for water. They are widely used as street trees in Crows Nest (photo at right), and are a favourite front-yard tree on smaller suburban blocks in Toowoomba.
There, they may be the only remaining plant of a “native” garden of the kind which was popular in the seventies. Most of the plants chosen tended to be short-lived species, which have now lived their life-spans and are only memories.
Fortunately, the weeping bottlebrushes are relatively long-lived and continue to grace many Toowoomba gardens.

Thursday, December 3, 2009

Ivorywood

Siphonodon australis
Family: CELASTRACEAE
The ivorywoods in Franke Scrub, Cawdor, are still flowering at present, even though some of the fruits are already ripe. These pretty trees are also called “wild guavas”. Their beautifully aromatic fruit is edible. The Franke scrub ones are rather small and dry as we've had little rain, but the fruits on well-watered trees can be 5cm diameter. The flesh smells beautiful and tastes good - something between an apricot and an apple in flavour - but it is unpleasantly gritty.
Ivorywoods have the capacity to be canopy trees, with a trunk diameter as much as 45cm, in their natural habitat which is the moist and dry rainforests of northern New South Wales and southern Queensland.
They are rarely seen approaching this size nowadays. They were much cut for their fine, straight-grained timber, which is good for turning, carving, inlays, marquetry, and making engraving blocks. Modern turners and carvers seek it out - but cannot often find it now.
No doubt many of the older trees, which produce good residential hollows for wildlife, were also cleared to make way for “better” trees, as part of the typical strategy in forests which are managed for timber.
Unfortunately, these very long-lived trees are slow-growing, so the large old trees which have vanished may take several centuries to replace.
Once established, ivorywoods are drought tolerant, and hardy to light frosts. They
prefer to spend their early lives in shade, so are good plants to establish in the shelter of shrubs. There, where they are in nobody’s way, they would be hardly noticed for years. By the time they are becoming pretty small trees, with dense canopies of dark -green, shiny leaves, the shorter-lived plants will be getting to the end of their lives.
If we are to leave something of our gardens for future generations, we should all be planting some of these slow-growers.