Xanthopyrenia Bachm., Nova Acta Acad. Caes. Leop.Carol. German. Nat. Cur. 105(1): 65 (1919).

MycoBank number: MB 5810; Index Fungorum number: IF 5810; Facesoffungi number: FoF 07654; 2 morphological species (Pérez-Ortega et al. 2016), molecular data unavailable.

Type species: Xanthopyrenia tichothecioides (Arnold) Bachm.

Arthopyrenia tichothecioides Arnold, Flora, Regensburg 52: 268 (1869).

Notes: The genus was described to accommodate the single species Arthopyrenia tichothecioides, a species occurring with seawater or spray on calcareous rocks (Thüs and Schultz 2009). This species and X. heardensis, the only other species described in the genus, were subsequently transferred to Pyrenocollema. Pérez-Ortega et al. (2016) showed that Collemopsidium as currently circumscribed is paraphyletic, so Xanthopyrenia might be the correct generic name for nonmarine Collemopsidium species (Fig. 28).

Fig. 28 Morphological and anatomical features of Xanthopyreniaceae. a Habitus Collemopsidium foveolatum-morphotype. b C. halodytes-morphotype. c C. ostrearum-morphotype. d Zwackhiomyces coepulonus. e Ascus from C. angermannicum. F Interascal filaments from C. cf. foveolatum. g Ascospore from C. cf. sublitorale. h Ascospore from C. angermannicum with gelatinous sheath. Scale bars: a–c = 1 mm; d = 0.5 mm; e–h = 10 µm


  • Xanthopyrenia tichothecioides