Other names: Compass Plant, Milk Thistle.
Family: Asteraceae (Daisy family).
Native of Europe.
Occurrence: A widespread and common weed of urban areas, roadsides, nature strips, degraded pasture etc. It is also an environmental weed.
It is sometimes called Compass Plant because the leaves often point in a north-south direction.
Prickly Lettuce is closely related to the garden lettuce (Lacuta savita). The main difference is the absence of prickles of garden lettuce. Its leaf shape is variable, depending on the cultivar.
Photo 1: Flowers and buds.
2: Some variation in leaf shape on the one plant. The leaves are prickly.
3,4,5: Prickly Lettuce. All from Castlemaine streets.