#The Cactaceae, N.L.Britton and J.N. Rose, orginele uitgave 1920

#Mediterranean Wild Flowers, Marjorie Blame, Christopher Grey-Wilson, 1993

#la Méditerranée de Marseille a Menton, Bournérias, Pomerol, Turquier, 1991

#Agaves of Continental North America, Howard Scott Gentry, 1982