The cob cactus is best known for the large, vivid blossoms. Especially floriferous, these are funnel-like to bell-shaped. They open during the spring and summer months. They emerge during the day and fade away by nightfall. Though the flower size can vary from one species to another, these can be around three inches or so in diameter and slightly longer in length. The blossoms are typically located towards the center or top of the plant. They occur mostly singly rather than in clusters. The blossoms range in color from white or yellow to all shades of pink, purple, orange, and red. Towards the throat, there may be a contrasting center.
A plant can have a large number of individual bodies growing in the form of a cluster. The bodies are somewhat small. Overall the plants are rounded to more globe-like or cylindrical. These will have ribs, and sometimes tubercles as well.
Originally the cob cacti were known as Lobivia. This Latin name for the genus was an anagram for Bolivia, the country in which the plants were originally discovered. Now, they no longer have a genus all their own for they’ve been lumped into Echinopsis.
Several of the cob cacti are particularly outstanding, including the following.
Cob cactus (Echinopsis hertrichiana) is among the most commonly grown species. This is particularly desirable as a houseplant. It has a shiny deep green body that tends to be globe-like.
With a fairly fast growth rate it can grow to be four inches or so across. This species tends to produce many pups or offsets. So it will definitely need a wide shallow pot.
The individual stems or bodies have very pronounced deep ribs and diagonal grooves. Along the edges of the ribs, which are particularly sharp, there will be areoles that are usually wooly and light colored. These have yellow and brown spines.
The vivid red to tannish-white, large blossoms can easily be up to two inches in diameter and slightly longer. Very floriferous, this species produces a large number of blooms over several weeks time.
This plant is used for creating hybrids with other cactus species.
Orange cob cactus is native to South America. This very floriferous plant comes in many varieties. The species tends to be oval and very small, perhaps an inch or so in height and across. This may produce offsets. The gorgeous blooms appear towards the top of the plant. The species often has crimson or white blooms. But, there are varieties with flowers in other colors.
Golden Easter lily cactus is native to South America. This plant is named for the funnel shaped, yellow blooms, which are quite numerous. The plant can vary in shape from cylinder-like to more globular. This species forms large clumps with many individual deep green stems. These reach about four inches tall. They have many crowded, closely spaced ribs. The spines are brownish-yellow.