Also known as Echinopsis ancistrophora ssp. arachnacantha, this small globular-flattened cactus is from Bolivia. This clumping species has stems that are dull green and more or less hemispherical with raised tubercles and whitish-brownish spines. The variety densiseta refers to the dense bristles on the body of the plant. The flowers are red to nearly iridescent violet. These plants are seedlings in 4-inch pots.