Fleshy Fungi of New Brunswick >> Inosperma rimosoides

Inosperma rimosoides (Peck) Matheny & Esteve-Rav.

Solitary in disturbed soil at edge of a woods road, most closely associated with Betula alleghaniensis, Populus grandidentata and Fagus grandifolia, Canoose Flowage Protected Natural Area, New Brunswick (18-08-17/01, 18-08-17/02)

Basidiospores medium brown in spore print, phaseoliform, smooth, with a very inconspicuous apiculus, 8.5-12.9 X 4.7-5.8 μm, D/d = 1.70-2.34 (average[51]: 10.0 X 5.1 μm, D/d = 1.95)

The pale yellow brown pileus characterized by strongly rimose (separating toward the margin) fibrils, lack of pleurocystidia and smooth spores with an inconspicuous apiculus serve to separate I. rimosoides from similar species. As it's name implies, it is very similar to the European species Inocybe rimosa, now placed in the genus Pseudosperma as P. rimosum. Inosperma rimosoides differs from P. rimosum in having a smooth (not pruinose) stipe apex.

The two collections illustrated here were quite dissimilar in appearance when viewed in the field, but are nearly identical microscopically. Using available literature there is no basis for separating them as distinct species. They were collected in the same locality about 70 meters from one another, so it appears they represent different mycelia.

Photo: D. Malloch (18-08-17/01, 18-08-17/02).