Saturday, February 23, 2013

The Snap, Crackle, Pop Tree

Excoecaria dallachyana
Family: EUPHORBIACEAE
A friend rang me last week to say that her exploding tree was doing it again! She had been out feeding the chooks, and the tree, about 20 metres away, had attracted her attention with its noise. Would I like to come over and hear it?
Well, how could I resist?
The tree was one of the original dry rainforest trees on her property, and was making the kind of noise that could teach Rice Bubbles a thing or two! Its tiny seed capsules were bursting open and releasing their seeds at a rate which made it look as though it was spitting with rain under the tree.


Even photographing them was not straightforward, as some of the little three-cornered capsules on my hand burst as I was holding them in the sun, spitting their three seeds away and knocking the other capsules about.
The tree snapped and crackled for at least three hours that day, and to judge by the quantity of seed it still had, is probably still doing it whenever the weather is warm and dry enough.
The seeds developed from inconspicuous winter flowers like these.

Note the plant’s tendency to have fresh green leaves on old-looking twigs. This helps to identify it in the wild. It grows as a shrub or small tree, usually to 4 or 5 metres, though it can apparently reach 15 metres in rainforest.



This plant isn’t often seen in gardens. Its common names include scrub poison tree, and blind-your-eye. Hardly good press, for what is a very attractive tree with a shiny green canopy. I usually see it in the scrub, where its shape is affected by other close-growing plants. The only garden-grown specimen I’ve seen was a particularly beautiful, well-shaped young tree with dense foliage to the ground.







Its bad reputation comes from its white sap. I doesn’t trouble the skin on my hands, but I wouldn’t risk it on my lips or eyes. There is a story that it troubled timbergetters in the old days, as chopping it with axes caused the sap to squirt about a bit, including into their eyes, resulting in blindness for several days.

I don’t think this plant would be any more dangerous in the garden than plants like frangipani, poinsettia and euphorbia, and common weeds like milkweed (often recommended for growing as a butterfly host) and the weedy little spurges that can be found in every garden. Like them, it would need to be handled with care if being cut or pruned. Putting a potentially harmful plant into a garden is something that should never be done without careful consideration.

2 comments:

Unknown said...

I find this blog particularly useful for plant traits and ecological notes that don't make it into keys or herbarium descriptions (young leaves on old twigs). Thanks.

Patricia Gardner said...

Thanks for you comment.
Trish