Introduction
It’s tricky to define a succulent in a single, all-purpose way. I know them when I see them, but I can’t think of a definition that covers every case.
The Tucson Cactus and Succulent Society has an online article by Mike Dimmitt:
The basic definition is simple. In general, the word “succulent” means juicy. A succulent plant is one that stores water in its tissues; hence it’s juicy…
The Details
His definition is as good as any I’ve found, and he adds useful nuance. “How juicy is juicy?” Where can the water be stored—roots, stems, leaves?
He also points out that succulents are more than “juicy”—they use the stored water. They don’t just store it; they actually draw on it during drought.
For me, bulbs and tubers are succulents even though their storage organs are mostly for food. Many of these plants also store plenty of water.
Bulbs remind me of another term: geophyte. I think geophytes are plants that spend part of the year underground and store food (and often water) in their storage organs. So, to me, bulbs are both succulents and geophytes.
Additional Reading: The ABCs of Succulents
