Cryptomyces maximusCryptomyces maximus is a species of fungus within the genus Cryptomyces. Cryptomyces maximus is the only species listed on The world's 100 most threatened species as being native to the British Isles.ClimateCryptotomyces maximus is a species of fungus comes from willow species as discovered in Finland in 1913. It prefers to live in damp and humid environments such as swamps. They can be found in a variety of different climates also so it is not just bound to one. They prefer both alpine and mountainous areas, along with the lowlands of Germany and the UK.