Common names: Midnight lady, Snake cactus (English)
Origin: South America
Untidy, spiny, sprawling to clambering, leafless succulent shrub generally up to 1.5 m high. Stems long, much-branched, often arching, usually 5-6 ridged, usually over 4 cm across and several metres long, rooting where they touch the ground; stem ridges with indistinct humps. Spines in groups, usually with three or more central, radiating spines up to 40 mm long and 6-8 smaller ones that are up to 10 mm long and held close to the stem. Flower buds not hairy. Flowers showy, white, nocturnal, base not spiny. Fruit fleshy, almost spherical, bright pink to red, generally without spines; pulp white, containing numerous blackish seeds.
This dangerously invasive species can form impenetrable mats that cover many hectares, out-competing and smothering virtually all other plants in the vicinity. Dispersal is mainly by rooting stems spreading and by seed - the fruit pulp, which contains the seeds, is eaten by birds and mammals and spread in their faeces.