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Wattle

Submitted by Peter on Tue, 2004-04-20 00:00
The first flowers on a wattle tree. The flower is bright lemon yellow and the leaves a lovely silver grey.

Wattle is a great winter flower and a fast growing fill plant. The image on the right is a lemon yellow wattle with silver leaves from my area of Sydney.

Some Australian plants develop silver grey leaves to survive the extreme heat in Australia. Wattle is the first tree to grow back in areas damaged by drought and bush fire. The wattle adapted to the dry weather by dropping their leaves completely. That part of the wattle that looks like a leaf is actually a leaf stalk spread out similar to a leaf. The leaf stalk contains far fewer pores than a leaf. Fewer pores means less water is lost through evaporation.

A silver grey wattle tree half grown among dead trees.

The image on the left shows a baby wattle tree in an area recovering from drought and fire. The dead trees in the background died during a fire. Regrowth is slow because of the drought that followed the fire.

The first buds forming on the branches of the wattle.

The wattle flower starts as a small bud shown in the next photograph on the right. Some trees are completely covered in flowers for one week while others will have just a few flowers due to a shortage of rain. Wattle flowers in Autumn so they can make use of winter rain.

There is a different variety of wattle flowering each week across winter. Australia's national flower is the Golden Wattle.

Scientific Name

Wattles, all 900 species, are part of the family Mimosaceae, in the genus Acacia. The Golden Wattle is called Acacia pycnantha. It's full scientific name is Mimosaceae Acacia pycnantha.

Botanists are the geeks of the plant world. Where we might whisper something to our spouse about procreation, they whisper propagation. Botanists do not use a capital letter for the start of the last word in the scientific name. When the name is emphasised, they like italics. Thus Acacia Pycnantha becomes Acacia pycnantha.

Prickly Subject

Some wattles have prickly leaves. The name Acacia was developed from the Greek word for point, 'akis'.

International Plant

Wattles developed when Australia was part of the Gondwana land mass, which included Africa, India, and South America. Wattles are native to those four continents.

Space Filler

When a Eucalyptus tree falls in a dry forest, wattles quickly fill the space protecting the soil from erosion and hold in the small amount of moisture. A new Eucalypt will slowly take over the space pushing out the wattle.

I used the natural healing effect of wattle when I rebuilt the garden in a house near a Sydney beach. The wind distorted the growth of many plants. The sun dried out the sandy ground. The neighbours said you cannot grow trees in the area.

Sydney Golden Wattle

First I planted dozens of the local Sydney Wattle or Sydney Golden Wattle, Acacia longifolia. They grow fast for five years then die due to borers in the branches. I let the wattles grow for one year then planted the trees and shrubs I really wanted. The wattles filled in the area and created a wind break for the slower growing plants. After five years the wattles were all dead and the space filled with a range of beautiful native trees including, the Cedar Wattle.

Cedar Wattle

Cedar Wattle, Acacia elata, is a large wattle that grows in to magnificent trees. Out in the open the branches grow in every direction producing a tree perfect for climbing. The Cedar Wattle has thick branches that survive large children. Most wattles have brittle wood that makes climbing dangerous. The wood snaps instead of bending. You have to stick to the thick branches and regularly inspect wattle trees for borers.

Hay Fever

Wattle is sometimes blamed for hay fever. I had a reaction to one species in one area where I lived for a few years. None of the species in my home town cause any problems. Dr Diana Bass is quoted as saying allergic response to wattle is rare. Lots of other experts agree that hay fever is more likely to be caused by grass pollen. I found text similar to the following on several sites.

Few people tested directly with pollen grains have a significant reaction. Pollen grains are much larger than grass grains and tend to fall straight to the ground below the tree, rather than blow around in the wind and get up people's noses. The strong scent of some wattles, however, can create an illusion of an allergic reaction in some people sensitive to perfumes.

From my experience and from observing others, once you have a hay fever attack, your face is sensitised for a couple of days and will react to almost anything. I do react to the strong chemical scents added to cleaning products.

Dry days are the worst because everything floats in the air, whereas on damp days everything is heavier and drops to the ground or sticks to damp surfaces. Sydney has rain in spring which reduces my hay fever to almost zero. Perth gets rain in winter leaving a long dry spring. When I lived in Perth, I would get hay fever for weeks at a time in spring. Perhaps the first attack of the season was set off by something other than wattle. Once the first attack happened, wattle was enough to irritate my sore eyes and nose.

My current house has grevilleas near the house and a small number of wattles at the far edge of my garden. I do not sit under the wattles when they are in flower. I mow the lawn after rain so that the water will hold down the grass pollen and everything else normally thrown up by the lawn mower. Our local bush has lots of banksias, grevilleas, and other species, but few wattles where I walk. The only remaining puffs of dust occur on those rare occasions when I open my wallet.

For More Information on Acacia

The CIA of Australia's plant world hang out at the Australian National Botanic Gardens. Visit WattleWeb for information from experts at Sydney's Royal Botanic Gardens. The Association of Societies for Growing Australian Plants have a section on wattle that includes information on eating wattle and a red wattle. World Wide Wattle contains additional information.

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