This member of the Cactaceae
family was described by Ladislaus Cutak in 1945. It is found in Guerrero in
Mexico, growing in grit with little water and some to much sun. The
caudex can grow up to twelve centimetres in diameter, the
leaves/stems up to 1,2 meters long. The nocturnal flowers are large
name from pene; 'thread' and Cereus another member of the Cactaceae
family, as to plant form. The species name after Mulford B. Foster,
1888-1978, an US-American plantsman and Bromeliad specialist.