Fleshy Fungi of New Brunswick >> Roridomyces roridus

Roridomyces roridus (Scop.) Rexer

Gregarious in leaf litter in mixed forest of Acer saccharum, Betula alleghaniensis, B. papyrifera, Populus tremuloides and Abies balsamea, Nepisiguit Protected Natural Area, New Brunswick (16-08-16/11).

Basidiospores forming a white spore print, ellipsoidal, smooth, amyloid, 7.2-8.9 X 4.0-4.9 µm, D/d = 1.55-2.03 (average: 8.1 X 4.5 µm, D/d = 1.80). Basidia 2-spored. Pileipellis a hymenoderm of subglobose cells, with clavate encrusted cells scattered within and just below the hymenoderm.

Although reported from Nova Scotia, this collection of R. roridus is the first record of the species in New Brunswick. It is recognized in the field by its exceedingly slimy stipe and under a microscope by its pileipellis of subglobose cells forming a hymenoderm. Collection 16-08-16/11 has smaller basidiospores than those usually reported for the species. For example, A.H. Smith, in his monograph of Mycena reports spores from two-spored basidia as 9-12 X 4.5-7 µm, well above the range of this collection. In addition, Collection 16-08-16/11 has peculiar encrusted cells occurring among the cells of the pileipellis, a condition rarely reported by other authors. Dr. S.A. Redhead, in his Ph.D. thesis (University of Toronto, 1975), appears to have been the first.

The yellow colour of the caps in the photograph is not quite accurate. The field notes record the colour as HSV 45:20-30:90, more of a pale orange brown.

Photograph: D. Malloch (16-08-16/11).