Abstract
Twelve fungi (ten ascomycetes, one asexual fungus, and one basidiomycete) were recorded from 833 samples of intertidal decayed wood of Avicennia marina collected from three mangrove sites at the Red Sea coast of Al-Leith city, Saudi Arabia. Common fungi were: Nia sp. (10%), Sammeyersia grandispora (8.5%), Fulvocentrum rubrum sp. nov. (5.8%), Marinosphaera mangrovei (4.2%) and Okeanomyces cucullatus (4.2%). Among the recorded fungi, six taxa are potentially new to science, of which Fulvocentrum rubrum sp. nov. is described in this article based on morphology and LSU rDNA sequence analysis. Phylogenetic analyses positioned the new species within the family Juncigenaceae, Torpedosporales. Fulvocentrum ruhrum is characterized by erumpent to superficial, membraneous ascomata with long and wide necks; asci with apical ring and 3-5-septate ascospores that are larger than those recorded in the two previously described Fulvocentrum species. Fulvocentrum rubrum differs from F. aegyptiacum and F. clavatisporum by having longer and wider ascospores that are surrounded by a gelatinous sheath and an apical ring in the ascus.