The egg-shaped, grey-green to dark green shoots reach heights of growth of up to 8 cm (3.1 in) with a diameter of 5.5 centimetres with around 17 notched ribs divided into tubercles.

The central spines are straight to slightly curved and thickened at their base and 1.5 to 2 cm (0.59 to 0.79 in) long or much shorter and inconspicuous.

The radial spines are 16 to 22 whitish, bristle-like, flexible and 0.6 to 0.8 cm (0.24 to 0.31 in) long.

The short and broad, funnel-shaped, yellow to orange flowers are up to 8.5 cm (3.3 in) long[3] Echinopsis densispina is widespread in the Jujuy province of Argentina at altitudes of 1500 to 3000 meters.

[4] The specific epithet densispina is derived from the Latin words densus for 'dense' and -spinus for 'thorny'.