The following conversation took place between my mum and me this Tuesday evening, while mum was dismantling a cauliflower for dinner:
R: Did you know that cauliflowers, cabbages, sprouts and broccoli are all members of the same species?
M: Yes, they're all related; they're all part of the same family.
R: No, they're more closely related than that: they're actually varieties of the same species. You know how every human being on the planet belongs to a single species? Well it's the same for cauliflowers and cabbages and stuff: they all belong to a single species.
M: I know—they're all vegetables!