Understanding Which Parts of Plants Spices Come From
Basil, mint, cilantro, parsley, and shiso are valued for the aroma of their leaves and are commonly classified as herbs. Cinnamon comes from tree bark, while peppercorns and cumin come from fruits or seeds. Cloves are flower buds, ginger and turmeric are rhizomes, and saffron comes from the stigmas of a flower. Knowing which part of a plant a spice comes from helps you avoid mistakes, like thinking cinnamon is a type of leaf.
Salt is a mineral, not an herb. Five-spice powder and curry powder are blends of multiple ground spices, unlike a single bay leaf. Curry leaves, on the other hand, are actual leaves, so you can't substitute curry powder using the same measurements.