The North American species of Pholiota, by Alexander H. Smith and L. R. Hesler.

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The North American Species of Pholiota

Lastly, a few comments on the gastroid genus Nivatogastrium are in
order. When Singer and Smith (1959) described this genus they related
it to Pholiota and nothing we have discovered since has indicated a different alignment. The gelatinous layer in the glebal trama was described as
hymenopodium, whereas the subhymenium was described as cellular and
non-gelatinous. The homologies as we see them now are that the gelatinous layer we have termed subhymenium corresponds to the hymenopodium in Nivatogastrium. This is not a contradiction, in fact it is very
likely a situation brought about by the gastroid condition. It is common
in the Hymenogastraceae for the one to three cells below a basidium to
inflate greatly thus producing a layer, whereas in Pholiota cells in a
similar position do not enlarge to form a layer and in fact are continuous
with the gelatinous layer. By definition the subhymenium is the layer
giving rise to the hymenium.
The real problem, however, is: How does Nivatogastrium fit into the
the picture of evolution to or from Pholiota? We believe the genus is a
gastroid extension of Flammuloides. It is difficult to visualize a lignicolous
futgus fruiting under the cold conditions of the snow-line in the mountains having its direct ancestors hypogeous in the soil. More important,
however, is the fact all major anatomical characters connect to Flammuloides and we know of no hypogeous species with such a combination
of features. Hence we regard the genus as a reduced agaric.
PRACTICAL IMPORTANCE OF PHOLIOTA
Edibility. From the standpoint of edibility we would list P. squarrosoides and P. barrowsii as the best in the genus and among the good
edible species on this continent. We cannot recommend P. squarrosa as
highly because it tends to develop a disagreeable flavor, and there are
certain strains of it which do not cook up well-flavored even if young
specimens are used. Also Shaffer (1965) has reported a "mild" case of
poisoning by it. The Pholiota aurivella group has long been used for the
table without much regard for species identity as it turns out. We recommend them as average, but the slime should be wiped from the pileus
before using them and this also removes the scales. Kiihner and Romagnesi (1953 p. 328) give P. adiposa one star-which is about where we
would rate the American variants. However, they list P. mutabilis with 3
stars meaning excellent, and Dr. Bille-Hansen of Copenhagen informs us
that in 'Denmark it is rated high because of its excellent flavor. It has not
been used much in this country as far as we are aware, but in the Pacific
Northwest it is abundant and could well be on the choice list. It is also
easy to recognize in the stages most desirable for eating by the numerous
recurved scales on the stipe.
However, Pholiota as a genus in the enlarged modern concept may
contain some species at least mildly poisonous. Also, since in their general