Brassicaceae

Alternate leaves on herbs with a pungent, mustard-oil taste; flowers are unmistakably cross-shaped with four petals set at right angles and six stamens (four long, two short), ripening into an elongated pod that splits from the base to release seeds from a persistent central partition.

The characteristic sulphur-containing glucosinolate compounds behind mustard's pungency are the same chemical family responsible for wasabi's heat and cabbage's sharp smell when cooked.

To check whether a plant belongs to Brassicaceae, compare the leaf arrangement, leaf type, flower symmetry, fruit type, and one distinctive marker together. A single feature can mislead; the family pattern is the combination.