Alascospora evergladensis Raja, Violi & Shearer
Etymology: Referring to the type locality, the Everglades
Sexual morph: Ascomata 125–232 × 135–236 µm, superficial to partly immersed, scattered, globose, subglobose or hemispherical and flattened at the base, membranaceous, ostiolate, light brown, translucent when young, darkening with age. Peridium ca. 5–10 µm wide, composed of hyaline to brown pseudoparenchymatic cells, with dark brown amorphous material deposited irregularly on the peridial surface, especially dense around the ostiole. Pseudoparaphyses sparse, hyaline, septate, filamentous, sometimes irregular, constricted or not at the septa, 20–40 × 2–4 µm. Asci 32–74 × 34–58 µm, (mean and SD = 60 ± 7 × 43 ± 6 µm, n = 25), bitunicate, thickwalled, globose to subglobose, short, pedicellate, containing eight irregularly arranged ascospores. Ascospores 30–40 × 12–16 µm (mean and SD = 36 ± 2.3 × 14 ± 1.3 µm, n = 45), ellipsoidal, 1-septate, septum thin and hyaline at first becoming thicker and darker in older ascospores, upper cell longer and wider than lower cell, hyaline when young, younger ascospores with minute hyaline, apical papillae, multiguttulate, becoming dark brown with age, surrounded by a translucent gelatinous sheath that appears as lateral wings in outline; each side of the sheath ca. 40–45 × 9–10 µm; in older ascospores sheath condensing and darkening to form a dark, appressed, verruculose ascospore wall covering. Asexual morph: undetermined. (Description from Raja et al. 2010)
Material examined: USA. Florida, Everglades Water Management District, Water Conservation Area 2A, phosphorus unenriched site U3, 26°17′15.07″N, 80°24′41.08″W, water temperature 19 C, pH 7, on submerged Nymphaea odorata petiole, 17 Nov 2008, Huzefa A. Raja and Helen Violi, SFWMD 1-1. (HOLOTYPE, ILL40789).
Notes: We establish Alascospora as a new genus in the Pleosporales incertae sedis pending molecular work on this genus. Thus far attempts to isolate this fungus in pure culture have not been successful due to failure of ascospores to germinate. In our current study we have examined more than 75 dead, decaying rhizomes and petioles of N. odorata but have found A. evergladensis only three times. This suggests that A. evergladensis might be a rare species or that the range of environmental conditions within which it reproduces might be quite narrow. (Notes from Raja et al. 2010)
Freshwater distribution: USA (Raja et al. 2010)