Friday, September 17, 2010

Hairy Birds Eye

Alectryon tomentosum
Family: SAPINDACEAEMy little tree is going to be a mass of flowers this year.
The flowers aren’t much to look at, but there are masses of them this year, so I'm expecting a great display of fruits to come in summer.
The tree is grown from seed, and only 11 years old, so I am interested to see how quickly it has reached the fruiting stage of its life. It has produced just a little fruit for a couple of years now, but this will be its first mass display.
I am interested that it is beginning what will probably be its major annual flowering at the same time as having the last of last season’s fruit on the tree. These were produced very late. Like so many of our Australian trees, Alectryons are opportunists, likely to flower at quite different times each year according to the rainfall offered by our erratic climate. The same tree also had fruit on it last May.

I love the way the little fruits open up - the red aril swelling to burst open the seed capsule and push at the little green cap until it falls off, to reveal a beady black "eye".

For more about this plant see May 2010

Friday, September 10, 2010

Corkwood

Duboisia myoporoides
Family: SOLANACEAE



Here’s a little plant I found flowering at Ravensbourne last week.






Corkwoods are slender little trees, growing to about 6m tall in the rainforest. Older trees have furrowed corky bark The leaves are dull, grey-green, and these little white flowers will be followed by juicy black berries which are eaten by birds such as topknot pigeons, figbirds, and catbirds.
The tree is quite common, tending to pop up in disturbed areas on the edges of rainforests, and spreads by root suckers. I imagine it is quite fast-growing, as such pioneer species tend to be.
The leaves were used as fish poison by aborigines. They are also poisonous to stock (and to people) but are valued as a commercial source of medicinal drugs. They have been used in medicines for travel sickness, and by eye specialists for dilating the pupils of the eyes, among other things. Workers handling the leaves are affected by the drug in them, which gives them a dry throat, headaches, and blurred vision, so handle this plant with caution, if at all!
A close relative of corkwoods, the western shrub Duboisia hopwoodii, is the source of the drug “pituri”, a narcotic which was widely used by aborigines before white settlement of this country. (The leaves were dried and mixed with the ash of wattle leaves, to make a mixture which was chewed.) It was regarded by them as a valuable trade item. Duboisia is related to tobacco, and the effects of pituri are apparently similar.
Don’t try chewing corkwood leaves, though. There is a real possibility of death resulting from even a small amount of it.
Although scientific study has found that populations of this plant from some areas are much less poisonous than those from others, it probably has no future as a garden ornamental!

Thursday, September 2, 2010

Evening Brown

Melanitis leda
My husband is a remarkable man. This butterfly flew across (or perhaps was blown, by the blustery August wind) in front of his car as he headed out the other morning. He stopped the car, ran into the house for his camera, headed out again, AND FOUND THE BUTTERFLY!
As those who have hunted this elusive creature know well, it is easy to see, on the wing when the bright russet of the wingtops is revealed, but can seem to disappear like magic as soon as it lands, even if you have had your eyes on it all the time.
This poor fellow was decidedly sad and battered. Below is a picture of a brand-new and beautiful one, taken a few years ago at Carnarvon Gorge.


We have never seen one at our place before, and think this one was lost and far from home.
Evening browns are secretive shade-lovers, usually seen flying low down in rainforest or scrub. The caterpillars are reared on native grasses, so for success this butterfly needs to have both environments close together.
Evening browns were probably once common in and around the area now covered by Toowoomba and its suburbs, and can still be found in the Murphy’s creek area. Here at the top of the Range, development has largely destroyed the environment it needs to live and breed.

Shining-leafed Stinging Tree

Dendrocnide photinophylla
Family: URTICACEAE
Some time ago, I was looking at seedlings of this tree in the Crows Nest Community Nursery (where they were planned for a revegetation project), and wondered if I would recognise the plants in the wild.

The answer, I discovered while bushwalking last week, was that I would not, until they bit me!
They actually have very few stinging hairs, so (as you can see) I handled them for some time without being aware of their identity. Then I moved a leaf in such a way as to brush the central vein on the back of the leaf, which is apparently where stinging hairs are most likely to be found, across two of my fingers.
Gwen Harden, Bill McDonald, and John Williams, in their excellent field guide “Rainforest Trees and Shrubs” (Gwen Harden Publishing 2006) describe the plant as having “hairs stinging, but not violently so”. My opinion is that they were at least as violent as those of the giant stinging tree (Dendrocnide excelsa), though admittedly the effect had worn off entirely after four or five hours. Perhaps the reason that this is a less dangerous stinging tree than its larger-leafed cousin is simply that any individual sting is likely to be the result of contact with only a few stinging hairs, affecting only a small section of skin.
In the same spot, there were plenty of small cunjevoi (Alocasia brisbanensis), whose juice is supposed to be a cure for this sting.
(See May 7, 2010 for more about cunjevoi.)
In the name of science, I applied a generous amount of the juice from a leaf-stem to one suffering finger, leaving the other untreated. I’m sorry to have to report that there seemed to be no difference, either in the pain or in the recovery time, between the two fingers.
Several of my bushwalking companions were also stung as they brushed past plants in the scrub, failing to notice them even after we had discussed the plant. Not all the leaves were as obviously toothed as these ones, and the foliage was easy to mistake for that of young bollygums (Neolitsea dealbata), which were also plentiful.


You can see on the photo above that the back of the stinging tree leaf is green, as opposed to the white back of the bollygum leaf below. It also has a characteristic pair of domatia in the angle of the lower leaf veins. (Double click for a closer look.)

This plant can become a 30m high tree, with a buttressed trunk. It is usually found in dry rainforest. Its succulent white fruits grow in densely tangled masses. (Technically, the actual fruits are very small, and the succulent bit is the swollen stem of the fruit.) They look delicious, and people are said to eat them, after tossing them in a paper bag to remove any stinging hairs. Apparently they taste like green apples - but putting a thing like this in your mouth seems a bit silly, to me. I imagine that one remaining stinging hair, affecting the mouth or throat of a sensitive person, would have the potential to cause serious harm. Best to leave them for the catbirds!