Yellow Varieties of Cactus
Golden Barrel Cactus (Echinocactus grusonii): This is a barrel-shaped beauty with a green body covered tightly with heavy gold-yellow spines. Blooms are golden as well. Golden barrel cactus grows easily indoors in a sunny or bright light situation. It is somewhat unusual to find cacti that are yellow with yellow blooms as well. Balloon Cactus (Notocactus magnificus): This multi-colored specimen features a definite yellow tint on the spiny ribs and on the top. The body is an attractive blue green that is indoor friendly, according to info on yellow varieties of cactus. This specimen will eventually form a clump, so plant it in a container that allows room to spread. Flowers of balloon cactus are yellow too, and bloom on the top. California Barrel Cactus (Ferocactus cylindraceus): Distinctly yellow with long, spreading central and radial spines covering a yellow body is the general description of the California barrel cactus. Some are tinted in other shades, such as green or red. These grow along the Discovery Trail in Lost Dutchman State Park, Arizona and California deserts. They are available for purchase in some nurseries in that area and online.
Cactus with Yellow Flowers
More commonly, yellow cactus color is found in the blooms. Numerous cacti have yellow blooms. While some flowers are insignificant, many are attractive and some are long lasting. The following large groups contain cacti with yellow flowers:
Ferocactus (barrel, globoid to columnar)
Leuchtenbergia (repeat blooms throughout year)
Mammillaria
Matucana
Opuntia (prickly pear)
This is just a small sampling of cacti that have yellow blossoms. Yellow and white are the most common colors for cactus blooms. Both indoor growers and larger ones that stay outside year round are found to flower yellow.