Formerly Sulcorebutia arenacea, also found as Sulcorebutia candiae, Sulcorebutia menesesii, Sulcorebutia muschii, Sulcorebutia glomeriseta (though the latter is here regarded as a species in its own right).

The name does not refer to spiders, as might be thought, but means “sandy (coloured)”. There are two very distinct forms of this very variable species. The nominate has very short, dense, mostly laterally pointing, pale spines giving the plant a whitish look; the other forms intergrade, and have orangeish or gingery coloured spines with a variety of spine lengths, straight and curved, body-hugging and projecting. Flowers are yellow.

Hentzschel & Augustin (2008) recognise four varieties; the nominate, plus:

• Weingartia arenacea var. candiae (Cárd.) Hentzschel & K.Augustin
• Weingartia arenacea var. kamiensis (Bred. et Don.) Hentzschel & K.Augustin
• Weingartia arenacea var. menesesii (Cárd.) Hentzschel & K.Augustin

Plants of this species in the collection include:

Weingartia arenacea var. arenacea Card1009

Weingartia arenacea var. arenacea Card4400

Weingartia arenacea var. arenacea HS30

Weingartia arenacea var. arenacea PHA731

Weingartia arenacea var. arenacea WR460

Weingartia arenacea var. candiae

Weingartia arenacea var. candiae BLMT638

Weingartia arenacea var. candiae FR774

Weingartia arenacea var. candiae GV135

Weingartia arenacea var. candiae HS29

Weingartia arenacea var. candiae JO694

Weingartia arenacea var. candiae Rep763

Weingartia arenacea var. kamiensis HS188

Weingartia arenacea var. kamiensis HS189

Weingartia arenacea var. kamiensis HS191

Weingartia arenacea var. kamiensis L 974

Weingartia arenacea var. kamiensis RH433

Weingartia arenacea var. kamiensis WR607

Weingartia arenacea var. menesesii Card5532

Weingartia arenacea var. menesesii FR775