The celery we get in supermarkets comes in the form of long, clean, tidy stalks that are eaten as a vegetable; sometimes the aromatic leaves are attached. The plant, though, also yields tiny pieces of fruit called celery seeds, which are used as a spice.

Although the seed is small, the flavour is strong - and, surprise, celery-like. It is used in alternative medicine. According to the University of Maryland Medical Centre, in the United States, the seeds are used as a diuretic, and to treat everything from inflammation to muscle spasms, anxiety and gout, although, "there are no scientific studies … that show whether celery seed helps treat these conditions or any others". It does say, however, that the seeds work as a mosquito repellent.

Celery seed is used in European and Indian cuisines. It can be mixed with other seeds and sprinkled over bread dough before it's baked. Celery salt is a commercial spice mix made by mixing ground celery seeds with salt, although this is something you can make easily at home. If you've had a Bloody Mary, you've probably tasted it, and it's also delicious when used as a dip for hard-boiled quail eggs, or sprinkled over chicken before roasting.