Starch 2
Our daily bread…
We thank rice, bread and potatoes for the fact that many plants build and store starch. Starchy grains and roots are our most important and cheapest sources of energy. Starch is food and forage, processed into alcohol and sugar, raw material for tablets or powder for cosmetics and finishes for yarn and fabrics.
Here they are ornamental but, in the tropics, important useful plants; the decorative leaves of the tropical Xanthosoma species resemble elephant ears. They are entirely edible, including their stems and rhizomes, however only cooked, because their calcium oxalates create uncomfortable side effects.
On several continents, people use the roots of Dioscorea species, or yams. They usually contain poisonous bitter substances, which are broken down through boiling, roasting or fermenting. Yams are so meaningful in the tropics that their name is used as a collective term for many different starchy tubers.
Have you ever considered what wallpaper paste is made of?