Monday, April 28, 2014

X is for … A-Z Blog Challenge

Well, lots of things really and it was a walk in my local park, in which, as you can see, the plantings are all Western Australia native plants, decided me.

The group of lower growing plants in the photo above are xanthorrhoeas or grass trees and they are unique to Australia. With their sweeping leaves and a trunk that is often burnt black by bush fires, which also clear away the dead leaf growth, it has a strong sculptural shape that is prized in gardens, to the point that when land is cleared for housing developments they are dug out and sold.

Because they are very slow growing - it can take up to twenty years for a trunk to form from a seedling - transplanting mature specimens is the best way to introduce one to the garden. They need a substantial amount of their roots in the original soil around them taken with them because it contains mycorrhiza, beneficial microbes vital to their survival. Those in the park have been there for thirty years but, because they were transplanted as mature plants, many are probably closer to a hundred years old.

That's not all that's different about grass trees. Their trunk has a very unusual structure. The centre is hollow and surrounded by flat leaf bases with aerial roots growing down inside. The leaves are long (between 2 and 3 metres in length), thin - and unlike most other leaves, which are flat, they have a square shape, which measures approximately 3 ½  mm on each side nearest the trunk end to 1 mm at the tip, and they are hard and brittle (you can snap them like a twig with little effort). When we were children we used to pull them out of the centre of the crown and chew the white, soft ends. They were moist and slightly sweet, with a texture something like fresh coconut.

  Grass trees can be tall and upright like this one which is around        
                                                              4 metres high or can have multiple trunks and crowns as the one
                                                              below once had. It has lost one of its trunks to fire.

Grass trees are particularly spectacular when they flower. A long, cream blossom spike up to two metres in length shoots from the centre of the crown and eventually turns brown with a scaly covering which is the stage these, with spikes from multiple crowns, are at.

Here in south western Australia the local indigenous people, the Noongars, call the grass tree balga and it was important for them in many ways. The flower spike was used as a fishing spear and its flowers were soaked in water to make a sweet drink while the oozing sap was used in spear making and as an adhesive.

There are two other similar Australian plants, the kingia and dasypogons, which look very much like the grass tree but do not belong to the same genus.

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