Eriostemon australasius Pink Wax Flower Nothing heralds the arrival of Spring in Sydney bushland better than the glorious pink flowers of Eriostemon, the Pink Wax flower and its close relations, the Boronias. This lovely shrub is not only common on sandstone ridges around Sydney but grows in heath, woodland and forests along the coast from Lake Conjola south of Wollongong to Fraser Island in south-eastern Queensland.
Until relatively recently, there were many species recognised as Eriostemon. However, most of these have now been transferred to the genus Philotheca, initially leaving only two species, E. australsius and a second species, E. banksii which grows on the northern tip of Cape York in far north Queensland. But now it appears that E. banksii has been reclassified as merely a sub-species, in other words, E. australasius subsp. banksii. E. australasius was the first Eriostemon to be described by botanists, so this species is known as the type species. Eriostemon belongs in the plant family Rutaceae, characteristically trees and Eriostemon australasius shrubs with conspicuous oil subsp. banksii glands in the leaves. Crush a leaf and take a sniff – this Eriostemon australasius fragrance is loved by some, subsp. australasius loathed by others! For Sydneysiders, it always brings back childhood memories of the Sydney bush.
The family has Gondwanan origins, although now widespread throughout tropical and temperate regions of the world. Probably the best known Rutaceae are the citrus fruit (oranges, lemons, limes, grapefruit, mandarins).
Don't confuse Eriostemon with Boronia: the former has five petals, the latter only four. There is another trap for the unwary too. Crowea saligna is almost identical to Eriostemon but, you won't find it flowering in spring. Look for it instead in Sydney bushland from mid-summer to early winter.
Wildflowers are at their very best in Sydney right now. Why not make time this weekend to go and see for yourself?
The road to West Head in Kuringai Chase National Park is famous for its wildflowers, so too is Muogamarra Nature Reserve just north of Cowan, open for just 6 weekends each year in Spring. Closer to home is the Kuringai Wildflower Garden in St Ives. All offer an excellent range of walks that showcase Sydney bushland at its very best.
Kuringai Chase:National Park www.environment.nsw.gov.au/NationalParks/parkHome.aspx?id=N0019
Muogamarra Nature Reserve: http://www.environment.nsw.gov.au/NationalParks/parkHome.aspx?id=N0456
Kuringai Wildflower Garden: http://www.kmc.nsw.gov.au/Services_facilities/Facilities_and_venues/Ku-ring- gai_Wildflower_Garden_and_St_Ives_Showground/Ku-ring-gai_Wildflower_Garden
Alison Downing, Kevin Downing, Brian Atwell Department of Biological Sciences, 8th September, 2014