Many lichens reproduce without sex (asexual reproduction). They make small groups of algal cells surrounded by fungal filaments. These "soridia" can be blown by wind. Some lichens just break up into fragments when they dry. Wind carries the pieces, which grow when moisture returns. Also, lichen fungi can reproduce sexually by forming fruiting bodies containing spores. These fruiting bodies are usually perennial, and may be long-lasting: some in the Swiss Alps have lived for over 50 years. After dispersal by wind, such fungal spores must meet with an algal partner to form a lichen.