A lichen is a distinct organism that is made up of two components: (1) the algal component is known as the phycobiont and generally consists of a green or blue-green alga; (2) the fungal component is known as the mycobiont and most commonly consists of an ascomycete although there are some in which the mycobiont is a basidiomycete. The number of lichen species is estimated to be between 13,500 and 14,000.2,13 Although it has been possible to separate and grow the phycobiont and mycobiont members of a lichen in culture, and to bring them together again, only rarely and under low nutrient and poor moisture conditions has the reconstituted lichen resembled the one from which it originated. Study of the conditions