borealis

Corollospora borealis, S.Tibell, Svensk Bot Tidskr 37: 2. (2016).

MycoBank: 817481                                                                  Facesoffungi: N/A

Sexual morph: Ascomata: 300-440 μm in diameter, globose to subglobose, superficial, black, solitary, ostiolate, on driftwood. Ascoma wall: 15-24 μm thick, consisting of an inner pale part formed by 3-5 layers of strongly flattened, polygonal or irregularly rounded, thick-walled concentrically arranged cells, outer layer forming a dark brown textura angularis. A mid-part is formed by 2-3 layers of shorter, dark brown cells c. 2-3 μm diam. The outermost part consists of 2-7 layers of pale brown, elongated hyphae that individually or in bundles partly reach out into the surrounding substrate and merge with the black subiculum. Ostiolum: central, c. 16 μm wide at the base and narrowing to c. 10 μm at the top, c. 20 μm high, at the base with a dark separation layer a few hyphae thick. Asci: eight-spored, thin-walled, ellipsoidal, 104-140 x 20-25 μm with 2-3-seriately arranged spores. Ascospores: at maturity fusiform, 5-septate, 33-44 x 8-11 µm, hyaline, without constrictions at septa; cells adjacent to the median septum distinctly enlarged as compared to the penultimate cells, without spines formed from the spore wall, but with usually two, sometimes just one or three appendages at the spore apices and the central septum surrounded by two whirls of flattened appendages formed by the recurved fragments of the exospore; semi-mature spores with a distinct longitudinal striation delimiting the parts of the exospore that later will split up and release the recurving appendages. Asexual morph: Undetermined.

Notes:

Corollospora borealis has no polar spines to the ascospores, but both apical and equatorial ornaments occur, which are characteristic of Corollospora. No young or semi-mature ascomata were found and the description is, therefore, in this respect, incomplete. Furthermore, there is no molecular data for C. borealis. Further collections and sequence data are required to resolve its relationship with other Corollospora species.

Key references:

Tibell (2016) New records of marine fungi from Sweden. Svensk Bot. Tidskr. 37(2): 43-54.

Werdermann E (1922) Corollospora maritima Werd., eine salzliebender Pilze von des Nordseekiiste. Notizbl Bot Gart Berlin-Dahlem 8: 248-250.

Kohlmeyer J, Volkmann-Kohlmeyer B (1989) Corollospora armoricana sp. nov., an arenicolous ascomycete from Brittany (France). Can J Bot 67: 1281-1284.

Image:

Corollospora borealis. A. Ascomata on driftwood. B. Section of perithecium. C. Perithecium wall. Note the textura angularis as seen in surface view of the upper surface of the section. D. Ostiolum, note the separation layer (SL). E. Ascus. F–G: Mature spores with meridional (black arrow) and apical (white arrow) appendages. A–G: Holotype.

The figure was taken from Tibell (2016).

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  Fig 1