Herzogia 20 (2007): 115–144 115 Notes on selected terricolous crustaceous lichens of Switzerland: Distributional, ecological and Red List data Hélène BEAUCHAMP, Mathias VUST & Philippe CLERC Abstract: BEAUCHAMP, H., VUST, M. & CLERC, P. 2007. Notes on selected terricolous crustaceous lichens of Switzerland: Distributional, ecological and Red List data. – Herzogia 20: 115–144. The determination of specimens collected within the framework of the Swiss Lichen Red List project yields information concerning 20 species of terricolous crustaceous lichens: Bacidia bagliettoana, Biatora subduplex, Bilimbia lobulata, B. microcarpa, B. sabuletorum, Buellia hypophana, B. papillata, B. punctata, Diplotomma geophilum, Helocarpon crassipes, “Lecidea” berengeriana, “Lecidea” hypnorum, “Lecidea” rufofusca, Lecidella wulfenii, Lopadium pezi- zoideum, Micarea lignaria, M. peliocarpa, Mycobilimbia carneoalbida, M. tetramera and Protomicarea limosa. The ecology and Swiss distribution of each species are discussed, and the species are evaluated according to IUCN meth- odology. Categories of threat are assigned to twelve species previously classified as DD (data deficient). The relation- ship between the extreme climatic conditions endured by these species and their muscicolous habitat is discussed. Zusammenfassung: BEAUCHAMP, H., VUST, M. & CLERC, P. 2007. Bemerkungen über ausgewählte, auf Erde wach- sende Krustenflechten in der Schweiz: Informationen zur Verbreitung, Ökologie und Roten Liste. – Herzogia 20: 115–144. Es werden die Bestimmungsergebnisse vorgestellt, die im Zusammenhang mit dem Projekt einer Schweizer Roten Liste für Flechten gesammelt worden sind. Es betrifft 20 auf Erde wachsende Krustenflechten: Bacidia bagliettoana, Biatora subduplex, Bilimbia lobulata, B. microcarpa, B. sabuletorum, Buellia hypophana, B. papillata, B. punctata, Diplotomma geophilum, Helocarpon crassipes, “Lecidea” berengeriana, “Lecidea” hypnorum, “Lecidea” rufofus- ca, Lecidella wulfenii, Lopadium pezizoideum, Micarea lignaria, M. peliocarpa, Mycobilimbia carneoalbida, M. te- tramera und Protomicarea limosa. Von jeder Art werden die Ökologie und die Verbreitung in der Schweiz besprochen, sowie die Arten nach der IUCN-Methode bewertet. Für zwölf, ursprünglich als DD (Daten unvollständig) eingeord- nete Arten werden Gefährdungskategorien festgelegt. Die Verbindung zwischen den extremen Bedingungen, denen diese Arten ausgesetzt sind, und ihrem Wuchsort auf Moosen wird besprochen. Key words: Lichenized Ascomycetes, biodiversity, Alps. Introduction Terricolous lichens are often found growing under conditions few other plants can survive. They colonize areas where, for reasons of drought, cold, lack of soil, or lack of nutrients, vas- cular plants do not grow well. They are also found in disturbed areas where they are often the first pioneer species to colonize the soil; yet they are soon crowded out and replaced by more competitive species, except in the least hospitable of conditions. Despite growing awareness of the necessity of protecting endangered species from extinction, the terricolous lichen flora of Switzerland has been largely ignored. Until the recent work of VUST (2002) concerning the terricolous lichens of Switzerland, no exhaustive study had been undertaken to analyze this group. The result of his study is a global picture of the terricolous