Morphological and anatomical investigation of Rhizocarpon disporum and its distribution in Razavi Khorasan province

Abstract

Rhizocarpon is a large lichen genus containing approximately 200 species worldwide that was, together with Catolechia, Epilichen, and Poeltinula, placed in the Rhizocarpaceae (lichenized Ascomycota). The genus is cosmopolitan and the species are mainly found in temperate, Arctic, and Antarctic areas. In the most widely-used classification, the genus has been divided into subgenus Rhizocarpon (yellow-green thallus containing rhizocarpic acid), and Phaeothalus (non yellow-green thalli lacking rhizocarpic acid). The taxonomy of the two subgenera occurring in the Razavi Khorasan province has been revised. 23 patches of thallus of Rhizocarpon disporum (Naeg. ex Hepp) Müller Arg. were taken from five localities in the altitudinal range about 1350-1730 meter of Razavi Khorsan province. The specimens were identified using a stereomicroscope, a normal light microscope with mounts in tap water, 10 % KOH and KI, the usual color tests and thin layer chromatography. Frequencies of Rh. disporum to the total number of the species of the genus with the quality of its distribution have been determined.

Keywords

• biodiversity
• rhizocarpon disporum
• morphology
• anatomy
• distribution map
• razavi khorasan