Keeping tiny flowers in bloom

VU scientists are developing new techniques to save one of Victoria’s critically endangered grassland plants.

The Spiny Rice Flower, or Pimelea spinescens, is a small native shrub threatened by land clearing and development, but scientists from the Applied Ecology Research Group are working hard to preserve it.

Dr Randall Robinson is leading the project and working with Dr Deborah Reynolds and the State and Federal Governments to protect this endangered plant.

Though previous conservation programs have tried to reproduce the species through cuttings, Dr Robinson says no one had figured out how to grow the plant from seed to re-establish it in the wild.

“They’ve tried but they haven’t cracked the code of what gets them to germinate.  We’re trying to crack the code,” he says.

The Spiny Rice-flower is relatively small, growing only about 10 centimetres tall and 20 centimetres wide. When grown from seed its roots can shoot downward about a metre towards the water table, meaning it can withstand destructive surface forces such as drought and fire.

When grown from cuttings, however, the Spiny Rice-flower’s roots grow to the side, making it more vulnerable to the elements.

Dr Robinson says one of the reasons it has been difficult for previous researchers to grow the plant from seed is because they believe it needs to pass through the stomach of an animal, which would have bathed the seeds in acid and scratched the seed coat, thereby helping it germinate.

“In most of the grasslands most of the animals are gone. So that’s a bit of an issue,” he says. “[We have] been treating the seeds with various types of acid but the most successful one we have found so far is a chemical called gibberellic acid. And that seems to work somewhat. The germination rates are still low but they’re improving.”

Dr Robinson says Victoria’s grassland and coastal wetlands are under threat from development. So it can be especially difficult to preserve small and unassuming plants such as the Spiny Rice-flower, which grows primarily in grasslands across central and southern Victoria.

“It’s not a glory species. It’s little, it’s got tiny, tiny flowers.”

Read the full story in Research Highlights magazine.


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