Hyphal pegs are bundles of unbranched hyphae which emerge from the hymenium and project as much as 250 micrometres from the surface of the lamellae (sometimes as little as 25 micrometres). A hyphal peg consists of between 10 and 50 (usually 20 to 30) hyphae. Hyphal pegs are usually cylindrical in shape but may be conical.

Hyphal pegs are best observed on cross sections of lamellae. Look for hyphal pegs away from the edge of lamellae, since they may be lacking there.

Hyphal pegs may be visible with a hand-lens as tiny projections on the face of the lamella.

Choose this state if: hyphal pegs are present. These structures are characteristic of Lentinus and also occur in some polypore genera.