Dissoderma paradoxum

Dissoderma paradoxum (A.H. Sm. & Singer) Singer, Beih. Sydowia 7: 69. 1973. [pdf]

MycoBank MB313311

AUTHORS: Martínez-Gil R., Ballester L., Ezquerro A. & Marques G.


Cystoderma paradoxum A.H. Sm. & Singer, Mycologia 40(4): 454. 1948. [basionym][pdf]

≡ Squamanita paradoxa (A.H. Sm. & Singer) Bas, Persoonia 3: 348. 1965. [pdf]

= Squamanita umbilicata Harmaja, Karstenia 27(2): 73. 1988. [pdf]

= Dissoderma umbilicatum (Harmaja) Bon, Doc. Mycol. 29(115): 34. 1999. [pdf]

= Squamanita basii Harmaja, Karstenia 27(2): 73. 1988. [pdf]

= Dissoderma basii (Harmaja) Bon, Doc. Mycol. 29(115): 34. 1999. [pdf]


Taxonomic Classification

phy Basidiomycota

sbp Agaricomycotina

cls Agaricomycetes

sbc Agaricomycetidae

ord Agaricales

fam Squamanitaceae

gen Dissoderma

sp Dissoderma paradoxum


Pileus initially convex, later flattened or even concave, up to 3 cm in diameter, with a slight and broad central umbo. Cuticle greasy, radially fibrous, purplish-brown towards the center, whitish towards the edges, and sometimes with remnants of the general veil in the form of yellow-orange scales. Stipe cylindrical and somewhat thickened towards the central part, up to 7 × 1 cm, formed by two well-differentiated parts; the upper part, approximately one-third of the total length, whitish and, like the cuticle, with purplish-brown fibrils; the lower part, similar in appearance and color to Cystoderma amianthinum (Scop.) Fayod, granulose or scaly and yellow-orange. Gills adnate, thick, whitish, with rough lamellar faces and a fairly irregular margin. Flesh purplish in the upper third and orange-brown in the rest, no odor or taste recorded.

Spores ellipsoidal, 8-10.2 × 4.6-5.6 µm, Q = 1.6-1.9, n = 85, hyaline, smooth, with 1-2(3) large guttules inside, surrounded by many smaller ones. Basidia clavate, tetrasporic. Lamellar trama formed by elements of different shapes, from nearly spherical to cylindrical, ellipsoidal, fusiform, and often constricted toward the central zone. Flesh trama formed by chains of cylindrical or broadly cylindrical hyphae, some constricted as in the lamellar trama. Pileipellis of cutis type, formed by parallel cylindrical hyphae, 6-12 µm thick, with abundant vacuolar content inside and encrusted pigment of brown color. General veil formed by chains of polyhedral, globular, pyriform cells, 20-45 µm in diameter, hyaline, with yellow-orange external content. Chlamydospores generally globular, sometimes fusiform, curved, and even triangular in section, 10-12.2 × 10.3-12.8 µm for globular ones and 8.3-10.2 × 11.7-18.3 µm for fusiform and more irregular ones, smooth, yellowish, with thick walls (1.3-2.2 µm) and numerous small guttules inside, generated at the ends of hyphae in the lower part of the stipe (the yellow-orange area). Clamps present throughout the carpophore.

Studied Material

La Rioja, Hornos de Moncalvillo, 42.385663, -2.578711, 730 m, group of 5 specimens growing on the ground, in a mossy area, within a mixed forest of Quercus ilex subsp. ballota and Pinus pinaster near several specimens of Cystoderma amianthinum. 08-XII-2021, leg. L. Ballester & R. Martínez-Gil, LB21120805 duplo RM-2716. The same location, 42.389309, -2.576655, 728 m, group of 6 specimens, 11-XII-2021, leg. A. Ezquerro, AEA0523.

Species References in the Territory
    • Arauzo S. (2008). Squamanita paradoxa recolectada en el Pais Vasco. Errotari 5: 21-25. [Esp: Vi][pdf]
    • Marcos J. (2017). Adiciones al catálogo micológico de la provincia de Salamanca. Micobotánica-Jaén XII(3): 208-236. [pdf]
    • Pérez de Gregorio M.À., Carbó J. & Roqué C. (2009). Algunos hongos interesantes de Girona. Fungi non delineati 44: 86-94. [Esp: Ge]
    • Román A. (2015). Squamanita paradoxa (A.H. Sm. & Singer) Bas. Asturnatura.com. [Esp: Le][pdf]
    • Torrent À. & Pérez de Gregorio M.À (1996). Squamanita paradoxa. Bolets de Catalunya 15: Lám. 747. [Esp: Ge]
Specimens in Scientific Collections
  • Sequenced Material

AEA: private herbarium of Antonio Ezquerro Antoñana; ARV: private herbarium of Alberto Román Vargas; ATI: private herbarium of Ángel Torrent Iglesias; ERD: private herbarium of Enrique Rubio Domínguez; ERR: Herbarium of the Errotari Mycological Association; JC: private herbarium of Joaquím Carbó; LB: private herbarium of Luis Ballester Gonzalvo; RM: private herbarium of Rubén Martínez-Gil.

Reference specimen marked in bold


Ge: ATI-110112002 and JC-20070911.5

Le: ARV-957 and ERD-6555

Lo: AEA0523*, LB21120805, and RM-2716

Sa: material not preserved

Vi: ERR-2006101905


Sequences in Public Databases and Obtained from Territory Material

AEA0523: GENBANK (ITS) OR578705


Fig. 1. Dissoderma paradoxum. LB21120805 & RM-2716. Fruiting bodies in situ. Photo: R. Martínez-Gil.

Fig. 2. Dissoderma paradoxum. AEA0523. Fruiting bodies in situ next to specimens of Cystoderma amianthinum. Photo: A. Ezquerro.

Fig. 3. Dissoderma paradoxum. A: Detail of a cut specimen. B: Detail of the stipe. Photos: R. Martínez-Gil.

Fig. 4. Dissoderma paradoxum. RM-2716. A: Spores from free spore print. B: Basidia. C: Lamellar trama. D: Flesh trama. Scale bar = 20 µm. Photos: R. Martínez-Gil.

Fig. 5. Dissoderma paradoxum. RM-2716. A: Pileipellis. B: General veil. C: Chlamydospores. D: Surface stipe hyphae and development of chlamydospores. Scale bar = 20 µm. Photos: R. Martínez-Gil.


How to cite this record:

Martínez-Gil R., Ballester L., Ezquerro A. & Marques G. 2023. Dissoderma paradoxum A.H. Sm. & Singer . SIM Sheets 42 (Updated on 20-IX-2023). DOI: https://doi.org/10.51436/SIMsheets/2023/42
Available at: https://micologiaiberica.org/services/en/Dissoderma-paradoxum