Tuesday, 7 August 2007

Occasionally 2...

Now this is an odd thing, one could wonder about. It is odd partly because it is a picture taken at 200x through my daughters' extremely plastic Digital Blue microscope. It is a closeup of a flower bud of an acacia, name unknown as yet, at the season when the buds are developing quite quickly. I collected it from a tree in the long and rambling GlenBurnie Road, Mitcham.
Here are the buds at 60x.
A flower stalk at 10x. Each cluster has about seven buds.
Another acacia species, as yet unidentified, the flower stalk of which is a series of rotating alternating buds on a stem. This is 60x.
Leaves and flower stalk at 10x. The alternation and rotation is evident here.
Stem and leaves. The greyish bud is I suspect the haven for an insect which infects the acacia. This tree had many such, a lot had turned burnt brown and decayed. when the insect had left.
Pods at 60x. They look like a fruit, but aren't. Acacia produce a seed pod similar in appearance to garden peas.
Here are the old pods, hanging like old decaying apricots.
The trunk system of the tree is very branched from just above ground level, not an uncommon system in Australia.
Another acacia, probably Acacia baileyiana, Cootamundra wattle, a flower, and part of a leaf, at 10x.
60x, the leaf becomes quite plastic, though rather gritty around where the leaf joins the stalk.
Flower at about 60x, is just a mass of yellow. The microscope is not good enought to focus clearly at that magnification and on such a mass.

GlenBurnie Road, Mitcham showing some of the acacia in flower. GlenBurnie Road was a private street, quite an uncommon concept in Australian cities, hence the lack of footpaths, kerbing, and the winding paving.

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Friday, 3 August 2007

Grass trees...

This is Xanthorrhoea, we used to call them yaccas when I was a kid, which is a long time ago now. Probably yacca was a corruption of yucca, the american plant which bears a minor superficial resemblance. These are in the western part of the Grampians National park, halfway to the SA border, 4 hours from Melbourne at a late hours drive.
They grow exceedingly slowly, 50 years ago I was told half an inch a year. I have accepted that as a fact, though I have no idea how true it is. They seem to flower occasionally too, especially after a good fire.
The flower stem grows quite long, this one is over a metre and they grow up to two metres, with a hard pile to the surface, small beak like seed capsules will be produced from the flowers. The flowers are white or cream, like a fine star. They are full of nectar, though not that scented.
The yacca is a source of gum. The trunk, which can grow several metres, consists of overlapping whorls of leaf like structures cemented together with a gum which is harvested for furniture making. My father did some of it when I was a kid, it was at the time a source of a small additional income to the pittance he was earning. The gum was cut off the trunk with an axe, seived though a rough iron seive and the resulting gum bagged.

This picture shows a section of the trunk of the Xanthorrhoea. The core seems soft but the gum on the inside of the leaflets is very strong and forms a hard case for the centre which seems to be the means by which the foliage is fed. The root ball is not particularly large although it is made up of many strong filaments. The leaflets were cut with an axe and the gum residue shaken out for resin.

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Thursday, 2 August 2007

mates...

These are my mates, often seen about the district. Of all creatures these birds seem to have the most fun. This is the same flock of cockatoos I have posted about before.


They are intelligent, sociable creatures. I have a short piece of video taken on my Pentax OptioWP which features the above birds. The centre bird has some object in its foot and is holding it up to eat it. The other two birds come in for a look, and the right hand bird takes it off the centre bird and scurries away The centre bird then turns to the left bird and complains. I haven't worked out how to add video to the blog, but you can probably access the Quicktime here.

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tree eating...

This tree is in Phillips Street, just around the corner from my house.. The tree is in the front of a corner house and is very large, perhaps 30 metres with a 1 metre bole. Like all gums it likes to branch, however the power lines run along the street so the great Aussie tree pollarding takes the form of a bite out of the west side of the tree. In ten years or so the tree will be tall enough that the lower branches will be over the power lines. I will keep you informed.

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Itchy tree...

I think this is a specimen of Callistemon sieberi. It is a street tree near the Morack golf course, one of my favourite haunts-not that I play the silly game-however I walk down this street quite often as one of my daily walks. I noticed the seed fruit stuck to the branches. It is an odd tree that should preserve its fruit even as the twigs that bear them grow into branches, and the shrub into a tree.

These fuit don't seem to have given up their seeds. The branches are three inches in diameter now so they have been many years attached to the limb. This may have some advantage to the plant in that it retains its seed until the optimal time to release it. Aroad side verge covered in couch grass may not confer such a moment. It may be fire is necessary, Callistemon are related to banksia which often do require a hot fire to open the fruit and release the seed into a bed of ash.
This shows the fuiting bodies a couple of years after flowering. The fruit is tightly collected in spirals around the limb.
This year, bottom, and last year, top, fruiting bodies. The limbs on which these flowers set are very thin,perhaps about 3-5mm, and alwys at the end of a limb.

The growing point of a limb. This encloses a tightly balled bunch of leaves.

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Occasionally...

This is an acacia- probably Acacia baileyiana- near my daughters' school. I have been watching it for several months as the buds develop-that may be another post-and for the weather to warm enough for the buds to burst. They finally made it the other day.
The tree is quite large, and forms a strong focus at the end of the street, and provides good shade in summer to the few cars that can park under it. Late July seems to be acacia flowering time, there are many splodges of yellow in the area, and in the parks. However, I think the flowering time depends on other factors, as wattles flower earlier the further north one goes. When it is sunny the trees are full of bees collecting pollen.
The flowers hang in bunches. I have no idea, although I wish otherwise, whether the flowering time this year is earlier than usual. We have had a very dry year up to May, since then it has been quite wet and cold, except for the last few days when it has got warm again. The flowering was bought on by the warmer weather.
Closeup. A few of the flower heads in the picture above have yet to burst. Each head is a ball of slightly more than a centimetre in diameter.

The yellow is intense. It reminds me of Sweden, where the early spring first blossoms were always yellow.

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