This feature refers to any swollen elements present in the pileus trama (and not to such elements that may be present on the pileus surface as part of the pileipellis). Distribution of swollen elements can be non-uniform, with some being more common near the lamellae and some near the pileipellis. Therefore, assess this feature from a cross section of the pileus, which extends well below the surface, to near the lamellae, or from at least two squash mounts of small pieces of tissue from the pileus trama near the pileipellis and near the lamellae.

Choose this state if: swollen elements (usually globose to subglobose) are present in the pileus trama, and the elements are smooth (not nodulose).

In Lactarius and Russula, swollen elements (sphaerocytes, sphaerocysts) occur in clusters (nests or rosettes) mixed with filamentous hyphae; such tissue is referred to as heteromerous (as opposed to homoiomerous tissue which is formed wholly of hyphae).