Bidens alba var. radiata, Bidens pilosa, Fam. Asteraceae
Erect annual herbs to 0.6m, mostly hairless green to purplish stems, square in cross section.
Other invasive plants
Invasive plants that are not prohibited or restricted invasive plants, but are known to spread readily and cause negative impacts, within the region.
|Form or habit:||Herb|
Opposite with serrated margins, lower leaves usually simple, ovate, 15-70 x 5-35mm, middle leaves usually pinnate with 3-7 leaflets, upper leaves smaller, often single or with 3 leaflets.
|Flower description:||B. alba var. radiata has yellow fluffy heads surrounded by white ‘petals’, up to 12mm in diameter. B. pilosa lacks the white ‘petals’; both have heads borne in terminal sprays.|
|Fruit description:||‘Seeds’ clustered on each flower head, black, up to 15mm long, flattened and 4-angled ending in 2-3 yellowish barbed bristles – the ‘cobblers pegs’.|
|Food source for:|
|Origin:||Cosmopolitan in warm areas|
|Notes:||Spread by: ‘seeds’ attach to ‘everything’ including clothing and fur. Invades/threats: minor weed in cane fields, common to abundant in disturbed areas such as roadsides, banks and fallow land, gardens. Notes: both are widely naturalised, but B. alba var. radiata is the more common species this region. Environmental weed.|
|Information sources:||Mackay Regional Pest Management Group (2018) Weeds of the Mackay Whitsunday Region Second Edition.|