What it’s called is irrelevant; what matters is what it is. The thing is clearly not a pod, it’s exactly the same as a pomegranate’s rind. That English-speakers call it a pod is no more relevant than the fact that they call the seed a bean.
Growing in a pod is not the only criterion. It is sufficient but not necessary. Rice and buckwheat are both kitniyos because they are cooked as porridge, which after all is the reason for the takanah in the first place.