Check whether the recipient wants a plant and where it can grow at home or work. Choose a compact specimen with a stable pot and clear individual care information. If the plant will be in a shared setting, follow the venue's rules and account for access by children or animals.
The message behind the grouping
Meaning, with a little thought.
Small details and continuing growth can express appreciation and patient attention. A personal note is more precise than claiming that a plant has one fixed meaning for every teacher.