Fleshy Fungi of New Brunswick >> Inocybe aurea

Inocybe aurea Huijsman

Picture of Inocybe aurea 02-07-07/03 Picture of Inocybe aurea 02-07-07/01 Picture of Inocybe aurea 27-08-08/04

Four collections, three illustrated here:

Inocybe aurea appears to be a rare species, reported up to the now mainly from Europe. Originally described from The Netherlands, it has been reported from Germany and Switzerland. It is included in Funga Nordica where it is stated to be rare. The website for the Herbarium of The Natural History Museums and Botanical Garden, University of Oslo (http://www.nhm.uio.no/botanisk/sopp/redgroup.htm) lists I. aurea as rare in its Redlist of Threatened Fungi of Norway.

Horak (Arctic and Alpine Mycology II, 1987) provided a short description of I. aurea in his key and a plate of excellent line drawings, including four spores from Huijsman’s type. The microscopic features of our New Brunswick material are mostly in accordance with Horak’s plate and description.

One point of disagreement between our material and Horak’s concern the plant associations. The three Swiss collections were from snow beds at an elevation of 2350-2420 m and grew in association with Salix herbacea, while the New Brunswick material was from a sandy pine plantation. Huijsman’s type was collected in dry sandy pine woods in The Netherlands, a habitat and elevation much closer to that of the New Brunswick collection. The greatly different habitat and plant association of the Swiss material suggests that it could be a species other than I. aurea.

The New Brunswick collections of I. aurea are characterized by 1) the yellow to yellow brown fibrillose pileus, 2) thin-walled and broad cheilo- and pleurocystidia and 3) narrow nodulose basidiospores. Inocybe ventricosa Atkinson is probably very similar. Grund and Stuntz (Mycologia 73: 655-674. 1981), who examined two collections of that species from Nova Scotia as well as the type from New York, described the pileus as yellow ochre and having a broad rounded umbo and a silky to rimose surface. The cheilo- and pleurocystidia are ventricose, thin-walled and similar in size to those of I. aurea. The only significant difference between I. ventricosa and I. aurea appears to be in the basidiospores. Those of I. ventricosa are described and illustrated by Grund and Stuntz (1981) as (6.5-)7-8(-9) X (4.5)5-6(-6.5) μm and thus shorter but proportionately broader than those of I. aurea. Unfortunately Grund and Stuntz did not provide very detailed information about plant associates (“Solitary on soil in moss, in hardwood forest or mixed stand…”) but their collections may not have come from sandy pine woods as have the New Brunswick and type collections of I. aurea The herbarium at Acadia University (ACAD) has uploaded to MycoPortal a record of I. aurea, collected by H. Stewart near Aldersville, Nova Scotia in 1966 and identified by Dr. Grund. Oddly, the series of papers on Nova Scotian Inocybe species by Grund and Stuntz make no reference to this collection.

Although collected in the same locality in sandy soil under Pinus banksiana, the four collections from New Brunswick differ from each other in some respects, most notably in the colour of the pileus, presence or absence of apical crystals on the cystidia and in the appearance of the basidiospores. Collection 02-07-07/03 is closest to the type as presented by other authors. The other New Brunswick collections have a darker and less overtly yellow pileus. The basidiospores of 02.07-07/03 are more distinctly nodulose than the others. However, these features may only represent the natural variation among basidiomata from the same location, perhaps affected by age and season.

Photo: D. Malloch (19-08-16]01).