Harrisia taetra grows like a shrub and reaches heights of 1 to 2.5 meters.

The stiff, needle-like, straight thorns, initially almost black, later turn whitish yellow.

The light to golden yellow, broadly ovoid to somewhat spherical fruits are smooth and covered with a few tiny scales.

[1] Harrisia taetra is widespread in Cuba in the Pinar del Río province on the Guanahacabibes Peninsula.

The specific epithet taetra means 'hideous, hideous, ugly, repulsive'.