Acanthocalycium ferrarii is a small tough cactus from Tucumán province in Northwest Argentina where it grows on very dry rocky substrates at elevations from 2000 to 2300 metres asl. Relatively rare in the wild and not often seen in collections it starts life as a chunky squat globose cactus gradually growing more columnar with age, usually solitary and unbranched and never very tall. It has an olive-green or greyish-green colouration with a flattish apex and distinctive ribs that are fuller and more protrubent around the areoles with pronounced vertically elongated tubercles giving it its chunky appearance. The spines are reddish-brown at the apex becoming more chalky with age. Its flowers are variable, sometimes red or yellow but usually pale orange. J.G. Lambert in his 'Cacti of Argentina' described them as the prettiest of the Acanthocalyciums.

First described by Walter Rausch, it was named in honour of his friend and colleague, Argentinian collector, planthunter and nursery owner, Omar Emilio Ferrari (1936-2010) who - as well as numerous articles and papers on cacti - published in 2005, together with Roberto Kiesling, the book '100 Cactus Argentinos'.

These are 5 year old seed-grown plants. Limited quantity.