Body. hanging;
Shoots thin, rounded, to 25 cm long., pale green, to 1 cm diam;
Ribs. about 7, tuberculate;
Areoles. to 7 mm apart, round, prominent, pale brown;
Spines. acicular, very thin, 6 - 7, 3-10 mm long., pale brown;
Central spine. occasionally 1;
Flowers. apical, 1.5 cm long., white;
Petals. ca. 9;
Fruit. spherical, pale yellow, c. 1 cm diam, watery;
Seeds. 1.2 mm long., glossy, black.
Habitat - Bolivia (Prov. Azero, Dept. Chuquisaca, road from Monteagudo to Camiri, 1100 m). An interesting species, clearly differentiated by its subterete and finely tuberculate shoots.

Ritter also mentions the following newly named species: P. gibberosperma Ritt.; P. gracilis Ritt., “ very slender, with many ribs and thin spines"; P. tarijensis Ritt., “weakly spined", ribs. fairly low (FR 880).