Cinchona Totaquina required a minimum of 70% crystallizable alkaloids of which at least 15% was to be quinine with not more than 20% amorphous alkaloids. There are at least 24 species recognized by botanists. There are likely several unnamed species and many intermediate forms that have arisen due to the plants' tendency to hybridize. Cinchona Cinchona is a genus of flowering plants in the family Rubiaceae containing at least 23 species of trees and shrubs. They are native to the tropical Andean forests of western South America. A few species are reportedly naturalized in Central America, Jamaica, French Polynesia, Sulawesi, Saint
Bark bread bark is the only part of a tree trunk that is actually edible, the remaining bark and wood is made up of cellulose which animals, including humans, cannot digest. The dried and ground inner bark was added in proportions like 1/4th to 1/3rd "bark flour" to the remaining grain flour. Erik Pontoppidan, the Bishop of Bergen, Norway, in the mid 18th century, recommended using elm, as it helped the often crumbly bark bread hold together better. The bark will, however, add a rather bitter taste to the bread, and give particularly white bread an unappetizing grey-green hue. Another problem is