In mycology, trama is the inner, fleshy portion of a mushroom's basidiocarp, or fruit body. It is distinct from the outer layer of tissue, known as the pileipellis or cuticle, and from the spore-bearing tissue layer known as the hymenium.
In essence, the ball is the tissue that is commonly referred to as the "flesh" of mushrooms and similar fungi.
Literally, "trama" is the Latin word for the "weft" or "woof" yarns in the weaving of cloth. This probably is related to the basidiocarp trama being "filler" tissue and that analogously the woof yarn in weaving is sometimes called "fill". Furthermore, the trama tends to be soft tissue, and in weaving, the woof yarn is not tightly stretched; it therefore need not as a rule be as strong as the warp yarn.