Honey may also contain pigments and scents. Go back to question 8b or go on to question 8c . This is an ancient philosophy that holds that plants contain a sign or signature which reveals how they can be used by people. For example, walnut resembles a human brain and therefore should provide brain remedies. Go back to question 8c or go on to question 8d .
Astringency is a sensation or feeling, a dry, puckery feeling in the mouth.
Go back to question 8d or go on to question 8e . Kairomones are chemical signals between different species where the signal mainly benefits the producers. Examples include the insect pheromones released by some flowers, flavonoids released by legume roots to attract the N 2 -fixing symbiotic bacteria and the semiochemicals released by corn leaves under attack by caterpillars. Go back to question 8e or go on to question 9a . Phycobilins harvest light for photosynthesis or sense light.