Zasmidium lythri (Westend.) U. Braun & H.D. Shin

Świderska-Burek, Urszula, 2020, A taxonomic revision of Zasmidium species occurring in Poland, Phytotaxa 437 (4), pp. 237-244 : 238-240

Zasmidium lythri (Westend.) U. Braun & H.D. Shin , in Bensch, Braun, Groenewald & Crous (2012: 320). ( Figs 1 , 2 )

≡ Cladosporium lythri Westendorp (1854: 240) .

≡ Cercospora lythri (Westend.) Niessl (1876: 1) .

≡ Stenella lythri (Westend.) J.L. Mulder (1975: 517) .

= Cercospora sanguinea Fuckel (1866: 30) .

EXS. on Lythrum salicaria : Sydow, Mycoth. German. 2799 (KRA–F 1932–86); Sydow, Mycoth. German. 3397 (KRA–F 1938–71).

Leaf spots indistinct, on the lower leaf surface, angular, sometimes covering almost the whole leaf surface, orangebrown on the upper leaf surface, greyish brown on the lower leaf surface. Caespituli amphigenous, but mostly hypophyllous, dense, reddish brown or almost olivaceous, sometimes covering almost the whole leaf surface; stromata none or dark brown. Conidiophores solitary or in fascicles of about 2–12, olivaceous to brown, slightly narrower towards the apex, multiseptate, unbranched, (25–)30–175 × (2.5–)3–4.5 µm; conidiogenous loci slightly thickened and darkened. Conidia pale olivaceous or pale olivaceous brown, cylindrical to obclavate, straight or slightly curved, 1–3(–5)-septate, rough, rugulose to verruculose, (15–)20–50(–63) × 3–4.5 µm; hila thickened and darkened.

Examined collections:—On Lythrum salicaria L. ( Lythraceae ). POLAND. Lublin Voivodeship: Długie Lake Reserve, 8 September 1982, leg. W. Mułenko (LBL), Durne Bagno Reserve, 29 September 1982, leg. W. Mułenko (LBL) ( Mułenko 1988). Podlaskie Voivodeship: Białowieża National Park, September−October 1989, leg. W. Mułenko (LBL) ( Mułenko 1996a,b). Pomeranian Voivodeship: Kluki in the Słowiński National Park, August 2001, leg. I. Adamska (SZPA 2388), October 2001, leg. I. Adamska (SZPA 2505), October 2003, leg. I. Adamska (SZPA 3818, 3865b).

Literature data:—On L. salicaria . POLAND. West Pomeranian voivodeship: Przelewice near Szczecin ( Madej 1969, 1974).

General distribution:—Azerbaijan, Belgium, Bulgaria, Estonia, Germany, Great Britain, Georgia, Italy, Korea, Netherlands, Romania, Russia, Spain, Switzerland, USA ( Braun & Melnik 1997, Crous & Braun 2003, Farr & Rossman 2020, Han et al. 2015).

Notes:—This fungus has been recorded on L. salicaria (from Europe and Asia), L. alatum Pursh (from North America), and L. hyssopifolia L. ( Braun & Melnik 1997, Crous & Braun 2003, Farr & Rossman 2020).

On Lythrum , only one other cercosporoid fungal species, Pseudocercospora lythri H.D. Shin & U. Braun , has been reported. Pseudocercospora differs from Zasmidium primarily in having inconspicuous conidiogenous loci, unthickened and darkened hila, and verruculose conidia. Additionally, P. lythri has shorter conidiophores (no longer than 90 µm) and conidia that are almost twice as long (up to 110 µm) and pluriseptate (1–13-septate) ( Chupp 1954, Shin & Braun 2000).

Figures

FIGURE 1. Zasmidium lythri on Lythrum salicaria (LBL, Długie Lake Reserve, 8 September 1982, leg. W. Mułenko). A. Leaf spots. B. Conidiophores. C. Conidia. Scale bars: A = 20 mm; B, C = 10 μm. U. Świderska-Burek del.

FIGURE 2. Zasmidium lythri on Lythrum salicaria (SZPA 3818). A. Hypophyllous patches of caespituli. B. Conidiophores erumpent through stoma and conidium in SEM. C. Fascicle of conidiophores. D. Conidium.