Hale, Mason E., Jr. Smithsonian Institution, Washington, DC.
Last reviewed:January 2020
Show previous versions
- Related Primary Literature
- Additional Reading
An order of ascolichens (class Lecanoromycetes, division Ascomycota) characterized by an unusual apothecium. Members of the order Teloschistales (formerly Caliciales) are ascolichens, that is, lichens [symbiotic associations of fungi (mycobionts) and photosynthetic partners (photobionts, including algae and cyanobacteria)] in which the fungus component is an ascomycete (a sac fungi, that is, any fungus of the division Ascomycota). These type of lichens are distinguished by an unusual apothecium (a spore-bearing structure in which the fruiting surface or hymenium is exposed during spore maturation). The hymenial layer originates normally; however, by the time that the spores are mature, the asci and paraphyses have partially disintegrated into a mass of spores and hymenial tissues known as a mazaedium. Most taxonomists assign five families to the order Teloschistales: Caliciaceae, Letrouitiaceae, Megalosporaceae, Physciaceae, and Teloschistaceae (see illustration); two other families, Microcaliciaceae and Ropalosporaceae, may also belong to the order. Together, there are approximately 2000 known species. In the family Caliciaceae, the disk is borne on a short stalk measuring 1–8 mm (0.04–0.32 in.) in height; this peculiar structure is also observed in members of the nonlichenized Roesleriaceae. These two families are so close that some species in either one may or may not lichenize symbiotic algae. The primary thallus of members of the Caliciaceae is a powdery grayish or lemon-yellow crust on soil or rotten wood. There are possibly 30 or more genera separated by spore septation and color. Members of the family Physciaceae, with about 20 genera, are more typically crustose, with sessile apothecia and a more fully developed thallus. See also: Fungi; Lichens; Mutualism
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 10,000 highly qualified scientists and 46 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information