A phylogenetic study of the genus Cookeina

Abstract

Cookeina, with seven recognized species, is one of the commonly encountered genera of the Sarcoscyphaceae (Pezizales) in tropical and subtropical areas around the world. Morphologically the species are distinguished by combinations of several features including ascospore shape and surface relief, presence and origin of apothecial hairs and presence or absence of gelatinous material within the cortical layer of the excipular tissue. Color of the hymenium, attributed to carotenoid pigments, is particularly variable in some collections especially those referred to as C. speciosa. In this study phylogenetic analyses were carried out using rDNA ITS and rDNA LSU sequences. Forty-four collections were studied which included a broad sampling of color variants of C. speciosa from a field site in Venezuela. The genus was shown to be monophyletic with several well-supported lineages. These analyses generally support the established, morphologically distinguished taxa within a monophyletic genus Cookeina. Collections referred to as C. speciosa segregate within a clade in which hymenial color differences are associated with groups within the clade. Cookeina sinensis is sister to C. tricholoma but is distinct from it; C. indica fails to resolve with any of the major clades. The placement of C. insititia is ambiguous but it falls within Cookeina and thus is considered in the genus Cookeina rather than in a separate genus, Boedijnopeziza.

• biogeography
• ITS sequences
• Pezizales
• Sarcoscyphaceae

We thank the following people who provided specimens for our use in this study: Sharon Cantrell, Peter Johnston, Richard P. Korf, Thomas Læssøe, Zheng Wang, Wen-ying Zhuang and the curators of C, CUP, DAR HMAS, KMAS, PDD. We appreciate the comments given us by Meredith Blackwell and Scott LaGreca who read the manuscript in various versions. Scott LaGreca also assisted us with various technical aspects. We gratefully acknowledge the support provided by NSF DEB-9521944.