AbstractThe ascomycetePloioderma hedgcockiiis unique in speculating; on living, as well as on dead needle tissues. The fungus was examined in green and dead needles ofPinus elliottiivar. elliottii using light microscopy. Teleomorph and anamorph stromata originated from sub‐hypodermal host tissue. In green needles, the hypnae where restricted to tissues outside the endodermis. The mesophyll cells adjacent to stromata showed abnormalities; the mesophyll distal to the stromata showed no symptoms despite heavy colonization by intercellular hyphae. In dead needles, all tissues, with the exception of vascular tissues, where colonized by inter‐ and intracellular hyp