Berkheya armata, in Afrikaans commonly known as the vlaktedissel (plains thistle) or grootdissel (big thistle), is a tussock-forming perennial that grows branched, erect stems to 40 cm from a woody rootstock. 

The leaves of the basal rosette are much longer than those occurring up the stems. All the leaves are oblong or lanceolate, shiny and hairless above, white-felted below. There are hard and thin spines along the undulating margins that are slightly rolled under. The leaves are up to 20 cm long.

The specific name, armata, is a Latin word meaning armed, referring to the marginal spines. 

One to a few yellow flowers are borne in spring.

The species distribution is in the south of the Western Cape, from the Cape Peninsula to Mossel Bay in the east and Tulbagh in the north. The photo was taken in Jonkershoek.

The habitat is clayey and granite flats and lower slopes in fynbos and scrub (Curtis-Scott, et al, 2020; Manning, 2997; Bond and Goldblatt, 1984; iNaturalist; http://redlist.sanbi.org).