[1] Oreocereus tacnaensis grows as a shrub with erect or spreading shoots that branch from the base.

The spines arising from the areoles are reddish brown to brownish yellow.

When fully ripe, they tear open from the tip and release the seeds.

[2] Oreocereus tacnaensis is widespread in the Tacna region of Peru at altitudes of around 3000 meters.

The specific epithet tacnaensis refers to the occurrence of the species near the Peruvian city of Tacna.