Cereus validus also known as Cereus forbesii is one of the most popular species in its genus. It is often mistaken for Trichocereus peruvianus by those who are new to cacti growing. The two are very similar in appearance, but cereus can be distinguished rather easily by the trained eye because its ribs are flatter than those of members of the Trichocereus genus. This is a good species for those starting out with cacti because it is a fast-growing, adaptable species.