Pet tree
A pet tree is a kind of keyring or mobile phone accessory that contains a very small cactus or succulent plant in a bell jar. The plant can be watered and, once it grows too large for the accessory, can be removed so that it may continue growing. Pet trees are popular in Japan, but are also available in the West. References

External links
Photograph of Pet Trees, by Meighan

Succulent plants
Pets