The garden's new display celebrates cycads, a plant group that dates back to the Jurassic period.

Wollongong Botanic Garden living collections curator James Beattie said some species were relatively unchanged since that time.

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"They're interesting relics, and they're true survivors," Mr Beattie said, explaining cycads had survived mass extinction events.

Cycads typically have a woody trunk with a crown of hard leaves and while they look like palms and ferns, they are not closely related to either.

The new collection includes five critically endangered plants and eight endangered species, some of which are native to Taiwan, Kenya and Tanzania, and the Philippines.

Mr Beattie said cycads were at great threat in the wild as the result of illegal poaching and habitat destruction, with demand for use in traditional medicines adding extra pressure.

Wollongong's collection includes plants ranging from about 10 years old to 80.

Mr Beattie said the garden had contained cycads since the 1970s, but there was a desire to enhance the collection.

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Many were in the shady undergrowth, Mr Beattie said, and there was no appropriate setting for the "sun-loving, dry-loving" cycads.

Under the guidance of cycad expert Stan Walkley (who donated five plants to the new collection), a new display was created, with improved drainage and soil.

Half of the new collection came from the estate of the late Dr Ian and Norma Edwards, who wanted to ensure their plants were safe after their passing.

A close friend of the couple, Colin Wilson, was in Wollongong on Wednesday for the official unveiling of the collection.

Dr Edwards was a passionate plant collector who served as director of the International Palm Society from 1998 to 2002.

Each plant was carefully extracted from the soil in the Sydney bayside suburb of Burraneer and brought to Wollongong by truck.

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The rest of the collection is made up of other plants replanted from elsewhere in the garden.

The cycad collection is located in the garden's north, near the Joseph Banks Glasshouse.

This Sunday, May 28 is a prime opportunity to check out the new display, as Wollongong Botanic Garden marks Botanic Gardens Day.

The event, running from 10am to 2pm, will include such events as behind-the-scenes tours and workshops, as well as plant sales.

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