Upward translocation of methyl violet and P32in sporophores ofLentinus tigrinusoccurred primarily in morphologically specialized hyphae in the center of the stipes. Hyphae in which most of the translocation occurred were loosely arranged, unbranched and seldom septate as contrasted to short, densely packed hyphae in the cortical zone of the stipes where little translocation occurred. More P82was translocated in a high‐transpiration environment than in a low‐transpiration environment. Nearly all translocation was stopped by killing the sporophores with propylene oxide, even though high‐transpiration conditions were maintained. The respiratory rate of hyphae in the central zone of the stipe was greater than that of hyphae in the cortical zone.