Genus Cortinarius Research Articles

Observations on the Bolbitiaceae, 13 & 14

Summary. 13. Agrocybe gasteromycetoides from Wyoming, North America, is described as new; relationships between some agaricoid and gasteromycetoid fungi are discussed. 14. The new names Agrocybe dennisii, A. hesleri, and Conocybe acutoconica are proposed. Twenty-two new combinations are proposed in the genera Agrocybe, Bolbitius and Conocybe. 13. A XEROMORPHIC MEMBER OF THE FAMILY Whilst examining material of the Bolbitiaceae in various United States herbaria, particularly that in the University of Michigan, a great deal of information on the family was amassed, and amongst all the new species which will ultimately have to be described the fungus considered herein deserves rather special treatment. It is of particular interest when comparison is made with a recent account of hypogeous cortinarii published by Thiers & Smith (1969). Although the fungi they described were considered true members of the genus Cortinarius, the characters exhibited have assisted our interpretation of the links between Cortinarius (Agaricales) and Thaxterogaster (Gasteromycetales). In the same way the present fungus contributes to an understanding of the relationship between the genera Agrocybe and the rather heterogeneous Galeropsis. The fungi described by Thiers & Smith were considered to possess in their genotypic composition an arrestment factor for basidiocarp expansion, probably best considered as causing a slowing down of the expansion of certain tissues of the basidiocarp, resulting in the stipe elongating only slightly or not at all, and the veil becoming thick and tough. In the fungus described below, the cessation of growth is apparently limited to the margin of the pileus and although a well developed stipe is formed, the pileus, during its paravelangiocarpic development, adheres tightly to it. Differentiation continues within the closed pileus to form the pileal trama, hymenophoral trama etc., and results in a series of gills enclosed in a 'peridium'. The gills or tramal plates ultimately separate one from the other and from the stipe by expansion of the lamellar gap; some of the gills also become bridged by veins or are finally costate. There is little doubt that this fungus would rightly fit into the old concept of the genus Secotium. However, the collector made a very significant observation: once the basidiocarps had been gathered some accidentally broke, and, surprisingly, a spore-print typical of an agaric was formed. Thus the hiatus between those characters associated with the agaricoid and gasteromycetoid basidiocarps becomes reduced. Indeed just as Thiers & Smith considered their fungi to be true agarics, it is proposed to treat the fungus present in the genus Agrocybe by virtue of its hymeniform pileipellis, colour of the spore-print, structure of the hymenophoral trama and morphology of the basidiospores. Indeed in gross morphology the fungus described below resembles members of the Agrocybe semiorbicularis-pediades

New Species of Galerina

During the interval since our last contribution appeared (Mycologia 47: 557-596. 1955), additional undescribed species of Galerina have come to light in both the flora of South America and that of North America. In this continuation of our field explorations we take great pleasure in acknowledging the financial assistance received from the National Science Foundation, Washington, D. C., and the Faculty Research Fund of the University of Michigan. The fruiting pattern of Galerina continues to be sporadic, and, for most of the species, less predictable than one would expect. However, as more collections accumulate it appears that careful study of the restriction of certain species to mosses in certain genera, such as Polytrichum, may be worth while. We have hesitated to place much emphasis on this feature at present because of certain tendencies among lignicolous species which indicate lack of specialization as to substrate, some species occurring both on wood of hardwoods and conifers, though they are usually more abundant on one than the other. The present paper contains 20 previously undescribed species, 3 varieties and one form previously undescribed. These taxa will all be treated in more detail in our forthcoming monograph. Color terms within quotation marks are taken from R. Ridgway, Color Standards and Color Nomenclature, Washington, D. C., 1912. It is apparent to us now, however, that the color of the various parts of the fruiting body is important taxonomically only when it deviates from a standard pattern. The standard pattern is an ochraceous-tawny to tawny cap, buff to yellow gills when young, and a honey-colored stipe. This pattern holds quite well for specimens from all areas from which we have collected as well as from those from which we have received material for identification. Consequently, for most species, matching plates in a color chart with colors of the parts of a fruiting body is by no means as essential as it is in the closely related genus Cortinarius.

Thaxterogaster—A New Link Between Gastromycetes and Agaricales

SUMMARY1. A new genus and two new species of this new genus are reported from Tierra del Fuego. This genus is here called Thaxterogaster, as Thaxter was the first to collect a representative of this interesting genus in the western hemisphere (Punta Arenas, Chile).2. Thaxterogaster is a genus of the Secotiaceae Corda, a true Gastromycete.3. Thaxterogaster has close affinity with the Cortinariaceae, especially the genus Cortinarius Fr.4. There are some data which tend to favor the assumption that Cortinarius is derived from Thaxterogaster rather than vice versa. These data are corroborated by certain observations at the type locality.

The Genus Gomphidius in the United States

I reviewed the salient characteristics of the genus Gomphidius in the introduction to the genus in the Agaricaceae of Michigan, 1: 170 (8). At that time only a few species had come to my notice in the field in this country, although I had seen G. viscidus Fr. and G. glutinosus Fr. growing in abundance in northern Europe. In European countries only four species of this genus are us? ually recognized in floras: G. viscidus Fr., G. glutinosus Fr., G. roseus Fr. and G. maculatus Fr. The British mycologists, however, report, in addition to these species, also G. gracilis Berk., and Rea (12) says the latter common in fir woods and heaths. Recent accounts of the American species of this genus have been published by Murrill (9 and 10). The species of this genus usually possess a viscid or glutinous, and hyaline, universal veil; in some species, however, this veil dry or merely moist, developing a slight viscidity only in very wet weather. The glutinous veil surrounds the young button, in the same manner as in the subgenus Limacium of the genus Hygrophorus; in the subgenus Myxacium of the genus Cortinarius; and in certain other genera of the Agaricaceae. In a few species, this veil scarcely or not at all evident, although it possible that even in these a blematogen present in the early stages. In most species this veil forms a definite teleoblema as shown by the fact that it separable from the pileus as a distinct, thick pellicle. Confusion may easily arise concerning the color of the universal veil, because of its tendency to become black in a number of the species. Berkeley says (2) the pileus of G. gracilis Berk. is covered with a smoke-colored gluten. How? ever, the veil of this species, like that of a number of others,

A Study of Development in the Genus Cortinarius

A Study of Development in the Genus Cortinarius

The Genus Cortinarius with Key to the Species

The Genus Cortinarius with Key to the Species