In the world of succulents, there are a number of species that are somewhat similar in appearance. Here are just a few that look alike.
Agaves and Yuccas
The Agaves and Yuccas are one of the most obvious examples. Both groups have sword shaped foliage in rosettes. Sometimes, these will have spines along the edges or tips. In both cases, there may be hair-like threads on the leaves.
The two groups are so similar that Yuccas are sometimes called false agaves.
The main difference in these two lies in their hardiness. While the Agaves occur naturally in warm climates, the Yuccas are native farther North. These can be quite hardy, depending on the species.
Gasterias and Haworthias
Some of the Gasterias and Haworthias are quite similar. Originally native to South Africa, these are both members of the Lily family. These look alikes have rosettes of foliage. Often, these will be speckled with contrasting color on the leaves. Typically, these spots will be white, giving the plants a leopard look.
In addition to the Gasterias and Haworthias, there are also hybrids created by crossing these two species. The hybrids are known as Gasworthias. These are similar in appearance to the parent plants.
The Crassula Family
There are quite a few rosette-forming groups of succulents that look somewhat similar. Three of these kinds are in the Crassula family, including the Sempervivums, the Echeverias, and the Aeoniums.
Of these, the Sempervivums tend to be the hardiest. These can be grown outdoors as perennials in cold climates. One obvious difference with the Sempervivums is that these often have thread-like structures on the leaves, which give them a cob-web like appearance.
Like the Sempervivums, the Echeverias are sometimes called hen-and-chicks. Echeverias are mostly native to Mexico and warmer areas of the New World. Though they can tolerate some cold, these plants are easily damaged by the wet winter soils that one sees in the East. Often, the foliage will have a whitish bloom and touches of red or other color. The color can vary greatly, depending on the kind being grown.
The Aeoniums are very tender, and can sometimes resemble Echeverias.