The North American Species of Pholiota
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. Kühner 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 aspect some species resemble the Galerina species of the Autumnalis complex, and since this group contains some very poisonous ones, no one should eat a Pholiota without being sure it is identified accurately and that the species is known to be edible. None of the species recommended above resemble possible poisonous species closely except P. mutabilis which in stature somewhat resembles the G. autumnalis group.
Kühner and Romagnesi list P. lubrica, P. spumosa, and P. carbonaria (Flammula carbonaria Fries sensu authors), under Dryophila as edible with one star—meaning average. We have all of these in North America, but in view of the many closely related species described as new and for which we have no information on edibility we cannot recommend them. We cannot help but call to mind the case of Togaria aurea (Fr.) W. G. Smith (Pholiota aurea of the present work) which is recommended as choice in Europe (3 stars in Kühner and Romagnesi), but in Alaska Wells and Kempton (1965) have found that a number of people are consistently poisoned by it. This pattern as regards edibility is a real threat in the group, and promiscuous testing of species whose edibility is not known is definitely discouraged.
Pholiota species as the cause of wood-decay. From our point of view based on field observations it is obvious that this genus plays a major role in slash disposal in both deciduous and conifer forests. As evidence of this we need only to cite the occurrence of Pholiota polychroa on oak slash 3-5 years old as observed by Smith near Ann Arbor, and the frequency with which Pholiota decorata and Pholiota spumosa occur on conifer slash in the Rocky Mountains and Pacific Northwest. In addition to these activities certain species obviously play an important role as root-rot fungi, namely Pholiota terrestris and Pholiota squarrosa. In the Trout Lake area of the San Juan Mountains of southwestern Colorado it was a common sight to see large clusters of this species at and near the bases of both aspens and conifers—it is often impossible to be sure of which conifer species, but Engleman Spruce is certainly involved. In view of this feature of Pholiota squarrosa locally in this one area, and the presence of variants in the species based on such features as color of the basidiocarps in one and an odor of garlic in another it is clear that the species is variable. From field observations, however, we suspect that perhaps one of the most active root-rotting fungi in the genus at least in the Pacific Northwest is Pholiota terrestris which fruits from buried wood and dead roots. The clusters nearly always appear terrestrial, which is why the species epithet was applied.