Three new species of Acanthostigma (Tubeufiaceae, Dothideomycetes) from Great Smoky Mountains National Park

Abstract

Three new bitunicate ascomycetes belonging to the genus Acanthostigma are described from terrestrial decomposing wood collected from Great Smoky Mountains National Park, USA. Phylogenetic analyses of the nuclear ribosomal 28S large subunit and internal transcribed spacer region placed all three species in the Tubeufiaceae and confirmed morphological analyses that these are distinct species. Expanded phylogenetic analyses of 28S large subunit including taxa throughout the Dothideomycetes confirmed the placement of Acanthostigma in the Tubeufiaceae. Acanthostigma filiforme differs from other Acanthostigma species in having longer ascospores with more septa. Acanthostigma multiseptatum can be distinguished in having longer asci and longer ascospores with more septa. Acanthostigma septoconstrictum differs in having longer setae and asci and broader, asymmetrical ascospores that are constricted at their septa. A dichotomous key to Acanthostigma species is provided.

• Ascomycota
• ITS
• LSU
• saprobe
• southern Appalachians
• systematics
• Tubeufia

This research was supported by a National Science Foundation award (DEB-0515558) to ANM. Sequences were generated at the WM Keck Center at the University of Illinois Urbana-Champaign. We are grateful for the help of Toni Atkinson, Preeti Chaudhary, Matthew Greif, Sabine Huhndorf, Dave Ketzner, Åsa Kruys, Ed Lickey, George Mugambi, Huzefa Raja, Alberto Stchigel and Larissa Vasilyeva who assisted in collecting samples. We also thank Carol Shearer and Huzefa Raja for providing the necessary equipment and training to conduct ascomatal sectioning. Lee Crane and Preeti Chaudhary are thanked for their review and encouragement of this manuscript.

Notes

2 An online interactive key to several species in the Tubeufiaceae also is available at http://www.discoverlife.org/mp/20q?guide=Tubeufiaceae