Curiosities

Some edible plants can’t be solely classified as vegetable, herb or fruit

There is always a pedant in the family, or an obliging guest at the table, ready to pounce should you dare call a tomato a vegetable. It’s a fruit, they say. Everyone knows that. Sure, you serve it up with lettuce, cucumber, herbs and a salad dressing, but it’s not a vegetable.

Well, I beg to differ. A tomato is both a vegetable and a fruit. Just like I am both a botanist and a (recent) grandfather. The point is, these are not mutually exclusive terms. Grandfather, like fruit, has a technical meaning: my son and daughter-in-law have a child. But the descriptor might be applied loosely to any person of a certain age, albeit with a slightly derogatory tone. To wit, ‘Out of the way, Grandpa!’

For a botanist like me, fruit is the stuff wrapped around a seed. Sometimes soft and squishy, sometimes dry and papery, sometimes hard as a rock. To the pedant botanist – don’t invite one to dinner if you want to get to dessert at a decent hour – fruit can only be what develops from the plant ovary. That is, the seed and the ovary wall. So an orange is all fruit, but much of a pear or apple includes the swollen parts of a flower outside the ovary.

Whichever way you slice them, some fruits are complicated. A pineapple is the fusion of fruits from many flowers, while a raspberry is an aggregate of many small fruits formed from a single flower. The samara of a maple is a dry, round fruit with a wing. Figs are odd – they have an inside-out arrangement, in the sense that flowers bloom inside a fleshy layer, which then swells further to become the luscious fresh or dried fruit we eat.

Even our pedant botanist would describe the tomato as 100 per cent fruit. No argument there. The seeds line the inner surface of two or more hollows within a fleshy ovary wall. Oddly, perhaps, botanists catalogue the tomato as a special kind of fruit called a berry – a fruit with one or many seeds in a fleshy pulp without an inner ‘stone’. Fruits that have a stone, such as the apricot, are called drupes.

While the tomato is undeniably a fruit, it is also quite clearly a vegetable, although this is not really a botanical term. We use it in a general sense to describe any plant or part of a plant. In fact, harking back to the parlour game and quiz show, if it isn’t an animal or mineral, it’s a vegetable.

In more common use, of course, a vegetable is a plant or plant part that we eat or, perhaps more narrowly, a plant that has a savoury taste or is eaten as part of the savoury course. The definition starts to get a little hazy here. Many ‘vegetables’ can be sweet, to varying degrees. Carrots, pumpkin and tomatoes spring to mind.

The first is a storage root, and the latter two are fruits, although you are unlikely to see a pumpkin in a fruit bowl.

This may not help things (he says, smiling) but a tomato can also be called a herb. Let’s deal with that pedant botanist again. He or she would say a herb is any plant with soft stems, perhaps adding that it should die after flowering. In that sense carrot, pumpkin and tomato plants would all be herbs, although sometimes a tomato might get a little woody at the base.

For you and me in our daily lives, a herb is something that we sprinkle on or add to mostly savoury food. Herbs tend to be leaves or flowers from an aromatic plant such as thyme, rosemary and sage – all of which are woody, and not herbs in a strictly botanical sense. The term ‘spice’ is reserved mostly for dried bark, roots or simple fruits (which we sometimes call seeds), such as cumin and black pepper.

So there you have it. A tomato is a vegetable, a fruit and a herb. Cumin is a fruit and a spice, produced by a herb. And thyme, like Schrödinger’s cat, can be both a herb and not a herb at the same time. I hope that’s all clear.