Freshwater Ascomycetes - Species Monograph

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Genus	Species	Author
Alascospora	evergladensis	Raja, Violi & Shearer
Class	Order	Family
Dothideomycetes	Pleosporales	Inc. sed.

MycoBank ID: 514032

Synonymy:

Description

Habit:

Ascomata superficial to partly immersed on submerged Nymphaea odorata petiole.

Ascomata:

Ascomata 125–232 × 135¬–236 µm, superficial to partly immersed, scattered, globose, subglobose or hemispherical and flattened at the base, membranous, ostiolate, light brown, translucent when young, darkening with age.

Peridium:

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.

Beak:

Ostiolae, lacking a beak.

Hamathecium:

Pseudoparaphyses sparse, hyaline, septate, filamentous, sometimes irregular in shape, constricted or not at the septa, 20–40 × 2–4 µm.

Ascus:

Asci 32–74 × 34–58 µm, (mean and SD = 60 ± 7 × 43 ± 6 µm, n = 25), bitunicate, thick-walled, globose to subglobose, short, pedicellate, containing eight irregularly arranged ascospores.

Ascospore:

Ascospores 30–40 × 12–16 µm (mean and SD = 36 ± 2.3 × 14 ± 1.3 µm, n = 45), ellipsoidal, one-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 gelatinous sheath.

Sheath:

Sheath 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.

Appendage:

None observed.

Culture:

Unable to culture.

Anamorph:

None observed.

Other info

Type & Location:

Everglades Water Management District, Water Conservation Area 2A, phosphorus unenriched site U3, 26°17'15.070"N, 80°24'41.08"W, water temperature 19 C, pH 7, on submerged Nymphaea odorata petiole, 17 November 2008, Huzefa A. Raja and Helen Violi, SFWMD 1-1. (HOLOTYPE ILL40789).

Other Specimens:

Everglades Water Management District, Water Conservation Area 2A, phosphorus enriched site F4, on submerged Nymphaea odorata petiole, January 2009, Helen Violi, SFWMD 1-2.

Substratum:

Submerged petioles of Nymphaea odorata.

Habitat:

Everglades, lotic.

Distribution:

USA (FL)

Pertinent Literature:

Raja et al.

Comments:

Additional Pictures

Asci.
Ascus.
Ascospore apex prior to ascospore maturity.
Bitunicate ascus.
Discharging ascus.
Sheath condensing on the ascospore wall.
Mature ascospore.
Ostiole.
Wall roughening.
Wall roughening.
Gelatinous ascospore sheath.

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