Cactus flowers (8)

1s, Tephrocactus alexanderi V bruchii.
2s, Opuntia drummondii.
3s, Hatiora cilindrica.
5s, Gymnocalycium vatteri.
8s, Heliantho cereus grandiflorus.
10s, Neochilenia andreaeana.
13s, Peireskia vargasii v. longispina.
20s, Neobesseya rosiflora.