Back to nature

Sunday, 21 August 2011

Skeletons of Eucalyptus leaves

This can be one of the most rewarding times of year to observe native plants flowering, whether in one's own garden or in the various wildflower gardens, reserves and sanctuaries that are open to the public. I am quite ignorant about native plants as I don't grow many of them, but I really enjoy seeing them in a bush setting, and on Friday I was fortunate to participate in a guided walk at the Ku-ring-gai Wildflower Garden in Sydney. Our guide drew our attention to many fascinating aspects that I would probably have been oblivious to had I been walking on my own.

Hakea sericea

The parade of native flowers begins in winter, and we saw a number of dainty blooms during our walk. Close inspection of these flowers shows how their shapes and textures are so different to traditional garden plants. Many wattles were smothered in bloom and a tiny, pretty, brilliant blue orchid-like flower on wiry stems was one of the noticeable flowers. Bright pink Boronia (possibly B. serrulata) blooms scented the air; and the spidery flowers of creamy Hakea sericea and bright red Grevillea speciosa were like small jewels in the grey-green landscape.

Kennedia rubicunda

We saw the intriguing and exotic-looking dusky red pea-like flowers of the twining Kennedia rubicunda and the brilliant yellow and brown Dillwynia juniperina - what we used to call 'eggs and bacon' when we were young. Larger inflorescences included a variety of dramatic Banksia species: their weird seedpods from last year's flowering still present on the branches of the shrub.

Resprouting Banksia

Part of this bushland had been subject to a controlled burn last year (to reduce the risk of bushfire to nearby houses), so it was interesting to see the effects of this on the landscape. The relationship between fire and the Australian bush is a long, complex and interactive one. Many plants recover from fire by sprouting from epicormic buds beneath the bark, and we saw a number of examples of this happening in this area of bushland. Other plants - particularly Eucalyptus - sprout from lignotubers at their base that are released from dormancy by fire. The seeds of some species depend on the heat or the smoke of fire for germination.

Regenerated grass tree with flower spike

Sometimes the death of the plant through fire is what actually triggers the dispersal of its seeds. The thick bark of many native trees protects them from the ravages of fire, and specimens such as grass trees (Xanthorrhoea) are also able to quickly regenerate after fire, which may also stimulate them to send up the tall flower spears: a phenomenon we were able to observe on our walk. The removal of undergrowth during a fire also allows fallen seeds to germinate more easily.

Scribbles made by insect larvae on bark of Eucalyptus haemastoma

During the walk we also became aware of the animal and insect life around us - from the signs of digging of bandicoots and possibly bush turkeys (sending a shudder down the spines of those in our group who have had these creatures in our own gardens) to the amazing markings made by the burrowings of the larvae of moths on the scribbly gums (Eucalyptus haemastoma), the remnants of a nest of termites that eat the fallen wood in the bush, and the skeletonising of many fallen burnt leaves by some tiny grub essential to the ecosystem.

There are a number of opportunities to visit native plant reserves in the coming weeks. The Ku-ring-gai Wildflower Garden at St Ives and the Muogamarra Nature Reserve near Cowan north of Sydney are both good places for an outing. The Muogamarra reserve is only open for six weekends in late winter and early spring, being closed for the rest of the year, and has a number of excellent bushwalking tracks. When I visited a few years ago, there was a wonderful display of waratahs in bloom at this time of year. The Australian Botanic Garden at Mount Annan is also an excellent place to visit to see native wildflowers.