Lapsana is a genus of flowering plants in the family Asteraceae, containing a single species, Lapsana communis (Nipplewort). It is native to Europe and northern Asia.
It is an annual or perennial herbaceous plant growing to 1-1.2 m tall, with hairy stems and clear (not milky) sap. The leaves are spirally arranged; larger leaves at the base of the flowering stem are often pinnate, with a large oval terminal leaflet and one to four small side leaflets, while smaller leaves higher on the stem are simple oval; all leaves have a toothed margin. The flowers are yellow, produced in a capitulum 1-2 cm diameter, the capitula being numerous in loose clusters at the top of the stem.
There are six subspecies:
In the past, a number of other species were included in the genus; these species are now treated in the genera Crepis and Lapsanastrum.
Away from its native area, Lapsana communis is naturalised, and sometimes considered an invasive species, in many areas around the world, including Australia, Chile, New Zealand, and most of North America.