Centipeda Cunninghamii

Centipeda cunninghamii, historically referred to as Myriogyne cunninghamii, is an Australian species of flowering plant belonging to the family Asteraceae. Known traditionally by the Koori name gukwonderuk, translated into English as old man weed, the plant has long been recognised by Indigenous communities for its medicinal applications. European settlers later applied names such as “common sneezeweed” and “scent weed”, though these terms have diminished in use. The species is associated with damp habitats, particularly along waterways such as the Murray River, and is identifiable by its distinctive leaf shape and strong pine-mint aroma.

Taxonomy and Nomenclature

The species was first formally described in 1838 by the Swiss botanist Augustin Pyramus de Candolle, who placed it in the genus Myriogyne. A later attempt in 1874 by Ferdinand von Mueller to reclassify it as Cotula cunninghamii was deemed invalid. In 1867, Alexander Braun and Paul Friedrich August Ascherson transferred the species to the genus Centipeda, establishing its currently accepted scientific name, Centipeda cunninghamii.
The generic name Centipeda derives from Greek roots meaning “one hundred feet”, likely referencing the multi-segmented appearance of certain floral structures. The specific epithet cunninghamii honours Allan Cunningham (1791–1839), an English botanist and explorer notable for his plant-collecting expeditions in Australia, New South Wales, and New Zealand. His collections formed the basis of Candolle’s first description of the species.

Botanical Characteristics

Centipeda cunninghamii is an erect or ascending perennial herb, typically reaching around 20 cm in height. It is generally glabrous, though some specimens may exhibit sparse woolliness. The stems are highly branched, creating a dense, low-growing habit adapted to periodically inundated environments.
Leaves

• Oblong to spathulate in shape
• Approximately 15 mm long and 3–4 mm wide
• Margins shallowly toothed or nearly entire
• Narrowed to the base, with an indistinct petiole

Inflorescence

• Small, globular flower heads, usually solitary and sessile
• Typically 4–8 mm in diameter, with colours ranging from green to red-pink
• Involucral bracts obovate and 2–3 mm in length
• Female florets arranged in 6–8 series; bisexual florets generally number between 10 and 30

FruitThe fruits are clavate achenes, about 2 mm long, with rounded apices and smooth upper surfaces above the ribs.

Ecology and Phenology

The species flowers mainly from spring to autumn, with seasonal peaks from September to February. Fruiting generally occurs between October and June. Its ecological niche consists of damp ground subject to periodic flooding, enabling it to persist across a range of soil types and moisture conditions.
Habitats include:

• Riverbanks, lakeshores, and pond margins
• Silty or muddy areas exposed by receding water
• Damp depressions in grasslands, dune systems, and pastureland
• Urban environments with similar moisture availability

Distribution

Centipeda cunninghamii is endemic to Australia but also occurs in New Zealand. It has been recorded across most Australian states and territories, including Queensland, New South Wales, Victoria, Tasmania, South Australia, Western Australia, and the Northern Territory. In New South Wales, it is present in coastal, tableland, and western subdivision regions. Occasional occurrences in Europe are believed to result from unintentional introduction.
The plant’s elevational range extends from coastal zones to montane regions up to approximately 600 metres above sea level.

Cultivation and Propagation

The species grows readily from fresh seed or vegetative cuttings, making it an accessible plant for cultivation. Owing to its vigorous growth habit, it may become invasive under favourable conditions. Its preference for moist substrates should be taken into account when managed in artificial or controlled environments.

Traditional Uses

Indigenous Australian communities have long valued Centipeda cunninghamii for its medicinal properties, applying it in treatments for wounds, infections, inflammation, and respiratory symptoms. Traditional methods of use commonly include:

• Topical application: Leaves are bound to parts of the body, allowing released oils—facilitated by body heat—to permeate the skin.
• Oral preparations: Leaves may be boiled or soaked to produce a tea, or mixed with emu fat to create a medicinal preparation.

Owing to potential toxicity in large quantities, traditional custodians and contemporary herbal practitioners emphasise careful dosage control when the plant is consumed orally.

Habitat Significance

Because of its reliance on moisture, Centipeda cunninghamii plays an important ecological role in riparian and floodplain landscapes. It colonises freshly exposed sediment, stabilising loose soils and contributing to microhabitat formation in temporary wetlands. Its aromatic foliage also influences herbivore interactions and local plant community dynamics.
Across its range, the species illustrates the adaptability of Australian flora to variable hydrological conditions and the importance of water-dependent ecosystems in supporting culturally significant plant species.