by Siti Farhana Maidin
This article is another instalment in our series, Know Your Park Lands Plants, where we introduce you to the myriad of species that populate your Adelaide Park Lands.
Cotton fireweed, (Senecio quadridentatus) sometimes known as cotton burnweed or sneezeweed, is native to Australia and New Zealand, but is also regarded in some locations as an invasive species.
It is very adaptable and widespread across Australia and New Zealand, and thrives in disturbed land, especially after fire.
Cotton firweed in Victoria Park / Pakapakanthi (Park 16). Photo above and top: Claire Page / iNaturalist.
Appearance
Cotton fireweed usually grows between 30 to 90cm tall. It features erect, hairy stems and lance-shaped leaves reaching up to 15cm long.
The plant blooms from late summer to autumn. It has clusters of small, white to pale yellow flowers. These flowers are particularly recognisable for their fluffy, cotton-like seedheads that easily disperse with the wind. Hence, its name, cotton fireweed.
Another image of cotton burnweed in Victoria Park / Pakapakanthi (Park 16), care of Claire Page / iNaturalist.
Habitat
In Adelaide, cotton fireweed can be seen on roadsides, cleared areas, and parks — including Victoria Park / Pakapakanthi (Park 16) in your Adelaide Park Lands.
The plant is well-suited to the local climate and can tolerate various soil conditions, particularly moist and well-drained ones. Its presence can be seen in urban settings as well as rural landscapes.
Ecological role
Cotton fireweed plays a vital role in local ecosystems by providing food and habitat for various pollinators, including bees and butterflies.
Its flowering period attracts these beneficial insects, which are crucial for pollination.
The seeds are also a food source for birds and small mammals, contributing to local biodiversity.
Cotton firweed. Pic: Noah Fenwick / iNaturalist.
Invasive potential
In some regions, cotton fireweed can be aggressive. This is especially so in disturbed habitats where it may outcompete native species.
In Adelaide, its spread needs to be monitored to ensure it does not negatively impact local flora.
While it offers ecological benefits, including support for pollinators, its potential to become invasive requires attention.
Cotton fireweed. Pic: pennyweight / iNaturalist.
Understanding this plant’s characteristics and role in the ecosystem can help in managing its presence in a way that balances ecological health with local biodiversity.
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Want to know more about the plants in your Park Lands? Head over to iNaturalist, where you can record, share and discuss your findings with fellow naturalists.
See the other plants featured in this series here:
https://www.adelaide-parklands.asn.au/know-your-park-lands-plants
