| Lichens are fungi with a specialized nutritional mode involving algae, or cyanobacteria, or both. Classification is based on the fungal partner, and around 13 500 species are known. The association is ancient, and the first ascomycete fungi with fruit bodies may have been lichenized. Adaptations to tropical habitats include extensive utilization of trentepohlioid algae, the production of large multi-celled spores capable of forming numerous germ tubes, and water-repellant hydophobins coating internal cell walls. Many tropical groups lack modern monographs and numerous new species are discovered in detailed studies. Lichens merit more attention in the tropics as bioindicators of habitat disturbance. |
