Plants of South Eastern New South Wales
Centaurea solstitialis
Common name
St Barnaby's thistle
Family
Asteraceae
Where found
Weed of grassy areas, waste areas, roadsides, and damp areas. Western Slopes, Kosciuszko National Park, the mountains to the north, ACT, tablelands, and the Sydney area.
Notes
Introduced annual or biennial herb to 1 m high. Bracts on the flower heads spiny. Stems much-branched, winged, greyish hairy. Basal leaves short lived, to 20 cm long, 60 mm wide, hairy to cobwebby, deeply dissected. Stem leaves alternating up the stems, 1–7 cm long, 2–8 mm wide, with soft, cobwebby hairs, margins entire to toothed, bases continuting down the stems. Flower heads green, oval to globular, 10–12 mm long, 4–15 mm in diameter, with many yellow florets 15–20 mm long, 0 petals. Flower heads single. Flowering: spring–summer.
General Biosecurity Duty all NSW. Noxious weed Vic.
PlantNET description: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Centaurea~solstitialis
(accessed 7 January, 2021)
This identification key and fact sheets are available as a free mobile application:
