Spice spices. Spices were among the most demanded and expensive products available in Europe in the Middle Ages, the most common being black pepper, cinnamon (and the cheaper alternative cassia), cumin, nutmeg, ginger and cloves. Given medieval medicine's main theory of humorism, spices and herbs were indispensable to balance "humors" in food, a daily basis for good health at a time of recurrent pandemics. In addition to being desired by those using medieval medicine, the European elite also craved spices in the Middle Ages. An example of the European aristocracy's demand for spice comes from the King of Aragon, who invested
Cassia (genus) to prevent desertification. "Cassia" species are used as food plants by the caterpillars of many lepidopteran taxa. For example, the skipper "Astraptes fulgerator" and the pierids "Catopsilia pomona" and "C. pyranthe" are all seen on "Cassia fistula". The latter utilizes several other cassias, as well. The plant pathogenic viruses cassia yellow blotch bromovirus and cassia yellow spot potyvirus were first described from "Cassia". Because the name "Cassia" is not precise, it is sometimes difficult to know what is meant by references to plants known as "cassias". Cassia gum, for example, is made from "Senna obtusifolia", a species formerly included in