Botany - Biological Classification Question with Solution | TestHub

Lichens typically do not grow in harsh environments in nature. Most lichens, particularly epiphytic fruticose species and those containing cyanobacteria, are sensitive to manufactured pollutants. Hence, they have been widely used as pollution indicator organisms.
Lichens are symbiotic associations of a fungus with a photosynthetic partner (called a photobiont or phycobiont) that can produce food for the lichen from sunlight.