Freshwater Ascomycetes - Species Monograph

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Genus	Species	Author
Phaeosphaeria	vilasensis	Fallah, Shearer & Leuchtmann
Class	Order	Family
Dothideomycetes	Pleosporales	Phaeosphaeriaceae

Synonymy:

Description

Habit:

Ascomata immersed on submerged, dead Juncus stems.

Ascomata:

Ascomata 114–128 x 96–122 µm, globose, scattered or in rows, immersed, papillate, ostiolate, membranous, dark brown.

Peridium:

Peridium 24–30 µm thick, with 4 to 6 layers of pseudoparenchymatic cells; cells 4–11 x 4–8 µm, outer cells brown, inner cells hyaline, textura angularis in surface view and in longitudinal section.

Beak:

Beak short, 4–10 x 4–8 µm, central, without periphyses.

Hamathecium:

Pseudoparaphyses cellular, 2.5–4.0 µm wide, constricted at septa, cells brick-shaped, with gel coating.

Ascus:

Asci 80–85 x 16–18 µm, clavate, fasciclate, few, fissitunicate, ocular chamber not seen; endotunica up to 600 µm long; asci tapering to a short hoof-shaped stipe at the base, with 8 overlapping biseriate ascospores.

Ascospore:

Ascospores 30–38 x 4–6 µm, fusiform, hyaline when young, becoming light brown at maturity, straight or slightly curved, 3-septate, constricted at the middle septum; middle cells slightly larger than the end cells, guttulate, possessing a gelatinous sheath.

Sheath:

Sheath gelatinous, fusiform at first, expanding in water to great length, up to 900 µm and staining with India ink.

Appendage:

None observed.

Culture:

Anamorph:

Other info

Type & Location:

U.S.A. WISCONSIN: Vilas Co., Sparkling Lake, UTM Zone 16, 291184mE, 5099214mN, on submerged dead stems of Juncus sp., 23 Nov. 1996, P.M. Fallah and J.L. Crane, P2-89(Holotype, ILLS 53991).

Other Specimens:

Same locality as above, P2-108, ILLS 53992.

Substratum:

Juncus sp.

Habitat:

Lakes (lentic)

Distribution:

USA (WI)

Pertinent Literature:

Fallah et al. 1999.

Comments:

Additional Pictures

Ascospore discharge.
Ascus dehiscence.
Pseudoparaphyses surrounded by gel as revealed by India ink.
Septate pseudoparaphyses.
Extended sticky sheath.
Peridium in surface view.

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