Turned out the magical fifth bean was, in fact a pea. Or is it? As the chick pea comes from the Fabaceae (bean) family, it’s fine to call it a bean as well. There seems to be quite a bit of flexibility in interpretation, not an entirely bad thing for the old chestnut of pea or bean to open up again.
The term nutrition experts use is pulse, which means “the edible seed of a leguminous plant”. This is different from an edible seed pod or fresh seed of leguminous plants - green beans, snow peas, fresh peas, etc - which have different nutritional qualities from pulses. You’ll see ‘vegetables and pulses’ mentioned in nutrition advice.