Daldinia: The nature of its concentric zones

Abstract The conspicuous concentric zonation occurring in stromata of species of Daldinia , based on studies on D. concentrica and D. eschscholtzii , is shown to result from a regular alternation of the orientation of the hyphae. The rings are all produced within a single growing season. There is no evidence to suggest that they are a result of successive abortion of perithecia.