Our home from home this week has been a hotel overlooking beautiful Lake Daylesford. Built in the 1930s to provide hydroelectric power to the town, as well as to attract tourism, the lake edge was landscaped by its European immigrant designers and planted with mainly exotic flora: willows, pines and hawthorns, which are now underplanted by those bullies of the plant world, broom, gorse and blackberries. Local development authorities watch these carefully, of course, and the noxious weeds are slowly being eradicated and replaced with more attractive indigenous understory species. Nowadays it's a lovely mixture of historical European shade plants and interesting local plants.
On our morning walk around the lake today we were interested to discover these wattle plants showing the transformation from their juvenile compound leaves into the mature phyllodes that characterise many of their species. The true leaves of all wattles are really the compound fern-like leaflets, but many, like this blackwood (Acacia melanoxylon) develop these modified flat leaf-like petioles soon after germination. A few species lack true leaves or phyllodes altogether and in these plants cladodes (which are simply modified stems) function as the leaves. The vertical orientation of the phyllodes and cladodes protect the plants from the intense Australian sun, since their vertical structures are not subjected to as much direct sun as the horizontally placed leaves.
Around a thousand of the 1381 species of wattle or acacia are found in Australia. More interestingly, 975 of these wattle species (out of 987 worldwide) are in the sub-genus "Phyllodineae" the group of wattles with Phyllodes like the ones we saw today. I think this stuff is really cool, by the way.
We picked samples of the leaves and phyllodes as well as a phyllodes with leaves growing from their ends to press and mount in our nature notebooks. It made for a terrific impromptu botany lesson, I must say!
Australia's national floral emblem is Acacia pycnantha, the Golden Wattle. Wattle Day is celebrated on the 1st of September each year. Just so you know. Jemimah does now too.
I love this stuff too. I'm crazy about plants, their structure, their history. Thank goodness for my nature journals, as it gives me an excuse to indulge in my craziness about plants.
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