Xerophyte

A xerophyte was a botany term for a plant that stored water in its root systems, often populating desert environments, (AUDIO: Exotron) and were a long-lived species. (PROSE: Meglos)

The Zolfa-Thurans were sentient xerophytes that could possess other creatures to shapeshift. (TV: Meglos)

The Fifth Doctor and Peri Brown found examples of xerophytes on an Earth colony planet. (AUDIO: Exotron)