The species is found growing in Rio Grande do Sul, Brazil.

The species was first described as Notocactus arnostianus by Lisal & Kolerik in 1986.

[1] There are between 21 and 30 spiralling ribs, with round areoles topped with white wool.

There are between 12 and 16 radial spines, which curve, and are from straw-yellow to brownish-red in color.

It can be found in Rio Grande do Sul, Brazil.