Atrotomentosus is from ater, black, and tomentum, woolly or downy.
Head silvery white, frontalia deep black, linear; tomentum of the thorax and of the abdomen more whitish than that of the female.
The upper surface of the pileus is smooth, or sometimes more or less covered with a tomentum similar to that on the margin.
Nothing can exceed the difference between the two, both in shape and tomentum.
The foxy flavor, the tomentum of the leaf, the pulpy flesh, and the usually continuous tendrils are all from Labrusca.