Cleistocactus strausii
Silver Torch cactus can thrive in low-nitrogen soil without facing the consequences of low nitrogen. Too much water will make the plant weak and lead to root rot. 
Least Concern. This cactus is locally abundant in its native land and has few local threats to its survival.
This cactus can be propagated by cuttings or seed.
Orbea variegata
This plant is popular in cultivation, and is often sold under its former name "Stapelia variegata". It has many common names, including starfish plant, starfish cactus, carrion cactus, carrion flower, toad cactus, toad plant. It is not closely related to the true cactus family.
When grown as an ornamental plant in temperate zones it requires protection, as it does not tolerate freezing temperatures. It is best grown under glass, in similar conditions to cacti.