Where do you find hydrocyanic acid? In nature, hydrocyanic acid is not normally found in its free form. In many edible plants, the hydrocyanic acid is freed by an enzymatic process from its original form (cyanic lipids, cyanic glycosides). Today, about 1,500 different edible plants are known to contain cyanic lipids or glycosides. The best known of these are manioc, bamboo, linseed, sugar cane and lima bean. The hydrocyanic content in the different plants varies widely: e.g. in manioc, values range from 5.5mg to 25mg/kg; in the lima bean, from 1mg to 31mg/kg. In Europe, cyanic glycosides are found in garden beans and peas. However, the cyanic glycoside content is much lower than in manioc or the lima bean. The highest levels of cyanic glycosides are found in the seeds of peach, apple, plum and cherry. In Europe, the highest concentrations of cyanic glycosides are found in the seeds of apricots and in bitter almond. The cyanic glycoside found in these two seeds is called amygdaline; if freed, it will develop up to 2,500mg/kg hydrocyanic acid. Hydrocyanic acid in its free form is found in tobacco smoke, exhaust fumes and interstellar space Name The colorless hydrocyanic acid gets its German name, Blausäure (blue acid), from its blue iron compound Fe7(CN)18, known as Berlin blue. Did you know that the word cyanic originates from the ancient Greek kyaneos, which means steel blue, amd has come down to us via Centaurea cyanus, the Latin name of the cornflower (also known as bluebonnet)?