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Roots of the achlorophyllous Epirixanthes papunana and E. elongata were sectioned in complete series in order to reconstruct the three-dimensional mycorrhizal colonization pattern within their tissues. Hyphal morphology, vesicles, as well as the exclusively intracellular mode of colonization indicate a Paris-type of arbuscular mycorrhiza showing a hitherto unknown colonization pattern:(1) the outer cortex is colonized by persistent straight-growing hyphae which branch in a cascading manner,(2) a specific layer (called layer 2) is inhabited by persistent hyphal coils,(3) in the cells of the anatomically distinct inner cortex parenchyma layer (called layer 1) the hyphae immediately degenerate, and (4) the layer outside to layer 2 (called layer 3) is either transitional layer 2 when penetrated from the outer cortex or the fungal material degenerates when colonized from the layer 2. This complex colonization pattern is a …