Cinnamon, the inner bark of a tropical evergreen tree, was used by wealthy Romans as perfume and others as an aphrodisiac. During the rainy season, when the bark is pliable, it is harvested for cinnamon production. As the bark dries, it forms long quills that are either cut into sticks or ground into powder. Two kinds of cinnamon are available -- Ceylon Cinnamon (Cinnamomum zeylancium) and Cassia (Cinnamomum cassia). Ceylon Cinnamon is perhaps so named because 16th century Portuguese explorers arrived on that island and, falling in love with the spice, immediately shipped off huge amounts to their home country. It has a buff-color and a gentle, sweet flavor: the lighter the bark, the higher quality the cinnamon. Cassia is dark red-brown, just a little bittersweet, and more pungent than its Ceylonese cousin.