Les bases de la systématique moderne des lichens

Abstract

Up to the end of the sixties, the systematic criteria used in lichenology, in particu­lar in floras, staid near those in use in the second half of the 19th century: morphology, structure and color reactions of thallus and ascocarps, structure, color, number of ascospores, conidia and conidiopho- res characters (i.e: endo- and exobasidiate). Recently, attention brought to new criteria founded upon the most recent researches, especially in cytology, anatomy and chemistry, overthrew the basis of lichen systematic: ascus apical apparatus, ascospore wall, ontogeny of ascocarps and pycnidia, lichen substances. Each of them is analyzed and illustrated by examples mainly chosen in french works. Use of elaborated mathematical methods as multivariable analysis is mentioned and the problem of the hierar­chy of the characters is discussed. © 1986 Taylor and Francis Group, LLC.