Flavor of wasabi, horseradish, mustard, capers, and jalapeño
Mustard, horseradish and a few others are sometimes grouped together as "pungent", which can also include aliums, ginger, and other strong flavors.

But it's a pretty fuzzy category.  Some people might not include hot peppers (but still include other types of "pepper").  Some might include other objectionable flavors that can overwhelm a dish if not used sparingly (so for me, cilantro, for you, capers).