Browningia (Britton & Rose 1920) Columnar plants that can reach considerable size, with clearly defined ribs and robust spines characteristic of each species. Several species within the genus exhibit a marked difference between the juvenile and adult phases, the latter being less rugged and having fewer spines. The flowers, light-colored and tubular in structure, typically open at night. They require a well-draining substrate and tolerate aridity well, though not excessively, at least in cultivation. They are somewhat prone to developing root atrophy, making it important to avoid excessive moisture. Etymology: In honor of Webster E. Browning.Place of Origin: Southern Peru and northern Chile.
Stetsonia ((Salm-Dyck)Britton & Rose 1920) Monotypic genus characterized by columnar stems that can reach considerable height, usually solitary. It features well-defined ribs and long, robust spines. Produces large, light-colored flowers. Requires very well-drained soil; although adapted to arid environments, in cultivation it needs occasional watering to prevent root atrophy. Highly susceptible to rot, so special attention must be paid to excess moisture. Etymology: In honor of Francis Lynde Stetson.Place of Origin: Northwest of Argentina mainly.