Original diagnosis: Pileus glaberrimus, levissimus, primo subemisphaericus (40''' diam.) dein explanato-expansus (60-70'''), ac saepe centro depressulus, margine repando, integro v. parce minuteque fisso, lateritio-gilvus v. lateritio-griseolus, medio non v. obscurior, iove sicco tenacello-fragilis, in senectute varie lobato-fissus, cute non difficile separanda; stipes albus, carnosulus, teres (50-65''' x 4-6''') basi inerassatulo-clavulatus, levis v. furfuraceo-squamulosus praecipue apicem versus, ubi etiam inerassatulus; lamellae saepius dimacriae, latiusculae (20-25''' x 7-8'''), confertiusculae, antice acute rotundatae, deorsum rotundato-subliberae, latiores, crassiusculae, superne saepius costao-rugulosae, acie undulata, subcrenulata pallida, primo fulvescentes, dein lateritio-gilvae, pulveraceo-tectae; caro pilei candida, compactiuscula, subexsucca, immutabilis, erassiuscula in stipitem ac hymeniophorum descendens; illa stipitis externe fibroso-tenacella, interne medullosa saepe per aetateom evanescens; odor intensissimus, nauseoso-virosus, peculiaris, fore Russulae foetidae putrescentis; basidia cylindraceo-clavulata (30-35 x 8-9), hyalina, sterigmatibus minutis; sporae elliptico-sublimoniformes (13-15 x 9-10), dense granuloso-farctae, rubiginoso-lateritiae.

English translation: Pileus completely glabrous, very smooth, at fist almost hemispherical (40 mm diam.), then applanate-expanded (60-70 mm), and often shallowly depressed in the centre, margin wavy, entire or scarcely and very shortly split, testaceous-yellow or testaceous-greyish, darker or not in the centre, in dry weather slightly tough to fragile, with age variably lobate-split, cuticle easily peelable; stipe white, slightly fleshy, terete (50-60 mm x 4-6 mm), slightly enlarged to hardly clavate at base, smooth or scurfy-squamulose, especially towards the apex, where it is also slightly enlarged; lamellae more frequently of two length, slightly broad (20-25 mm x 7-8 mm), slightly crowded, acutely rounded at the outermost end, rounded-subfree below (at the attachment?), broader, somewhat thick, in the upper portion often intervenose-wrinkled, edge wavy, subcrenulate pale, at first pale brown, then testaceous-yellow, covered with powder; context of the pileus pure white, slightly dense, juiceless, unchangeable slightly thicker in the stipe and continuous with the pileus; that of the stipe externally fibrous slightly tough, internally medullary often vanishing with age; smell very strong, nauseous-stinking, peculiar, almost that of rotting Russula foetida; basidia cylindraceous-clavate (30-35 x 8-9), hyaline, sterigmata very small; spores ellipsoid-sublimoniform (13-15 x 9-10), content densely granulose, rusty red to brick red.

Commentary: In the latin diagnosis there are some terms that may be ambiguous. The term "dimacriae" is a Greek compound, rarely used and taken to mean “of two dimensions”; referring to lamellae it probably should be interpreted as “of two lengths”. The term “hymenophorum” can refer to the hymenium but can also mean “pileus”. A possibility that makes sense might be “and coming down from the pileus”, that is to say “… and continuous with the pileus”. Another might be “but reduced in the hymenophore (i.e. narrower in the part of the stipe where the lamellae are attached”. Thus far we have been unable to study type material of this taxon. Based on the diagnosis, it is not possible to determine whether this is a Hebeloma, although the description of the spores makes it unlikely.