Description: Succulent shrubs, spinose; segments ± cylindric in cross section with elevated tubercles.
Leaves terete, falling very early. Areoles elongated, depressed, filled with white woolly hairs; glochids present but very small; spines 3 or more, sometimes absent on cultivated plants.
Flowers with ovary strongly tuberculate, depressed at apex.
Fruit ± globose.
Distribution and occurrence: World: 18 species, South America. Australia: 2 species (naturalized), Qld, N.S.W.
Text by G. J. Harden