This member of the Euphorbiaceae family was given this name by Ferdinand Albin Pax in 1831. It is found in the lowlands of Argentina, Brazil and Paraguay, growing in a well drained soil with some water and some sun. The Caudex can grow to ten centimetres, the whole plant up to 130 centimetres in height.
The name is derived from the Greek words κνίδη (knide), meaning 'nettle' and σκολος (skolos), meaning 'thorn' or 'prickle'. The species name after Emil Hassler, 1864 - 1937, a Swiss physician, ethnographer, naturalist and botanist.

