Hydrophilomyces atroseptatus T.Majewski

Santamaria, Sergi & Pedersen, Jan, 2021, Laboulbeniomycetes (Fungi, Ascomycota) of Denmark, European Journal of Taxonomy 781, pp. 1-425 : 48

Hydrophilomyces atroseptatus T.Majewski

MB#363459

Fig. 6G

Polish Botanical Studies 7: 56 ( Majewski 1994b). –

Type: “ On Limnebius aluta (Bedel) , Sw. Smolniki , 12.8.1974, leg. A. Sarna ( T.M. 1482 – Holotype)”; KRAM. [ Poland]

Diagnostic features

Main appendage axis with dark constricted septa separating secondary branchlets or antheridia from corner cells ( Fig. 6G , arrows); stout, not exceeding the perithecial apex, consisting of 9–12 flattened cells. [Detailed description: Santamaria 2003]

Distribution and hosts

Known from Poland (type) and Spain on Limnebius (Col. Hydraenidae ) ( Santamaria 2001a). According to Majewski (2008) the record of Hydrophilomyces limnebii on L. aluta ( Balazuc 1990) from France probably belongs to H. atroseptatus .

Collections examined from Denmark

On Limnebius aluta Bedel, 1881 (Col. Hydraenidae )

DENMARK – Nordøstsjaelland (NEZ) • Storø i Gurre Sø ; 56°2.208′ N, 12°29.057′ E; UC41; 7Apr. 2020; JP 1628; JP det.; ZMUC C-F-124366 . – Sydjylland (SJ) • Braenøre Mose ; 55°23.906′ N, 9°25.714′ E; NG23; 5 Aug. 2018; JP 1168; JP det.; ZMUC C-F-123693 .

Remarks

First record from Denmark. The Danish material consists only of young thalli. Nevertheless the distinctive dark septa of this species confirm its classification ( Fig. 6G , arrows). Hydrophilomyces limnebii also occurs on Limnebius , but may be easily distinguished by the absence of dark septa in corner cells and by the strongly bent perithecium. A photo of H. atroseptatus is given here for the first time, although in immature condition.

Figures

Fig. 6. A–F. Kainomyces isomali Thaxt. A–B. Mature thalli showing the rostrum (ro) on the perithecia. C. Detail of an immature perithecium showing numerous wall cells for each row and the subterminal outgrowth on the perithecium. D. Detail of basal area of perithecium showing brown spots. E. Detail of receptacle with antheridia (an). F. Detail of the lower receptacle showing comb-like pigmentation. – G. Hydrophilomyces atroseptatus T.Majewski. Young thallus where darkened septa on the base of secondary branchlets are arrowed. Scale bars: A–B, F–G = 50 µm; C–E = 20 µm. Photographs from slides ZMUC C-F-124250 (A), ZMUC C-F-124252 (B), ZMUC C-F-124002 (C–F), and ZMUC C-F- 123693 (G).