Freshwater Ascomycetes - Species Monograph

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Genus	Species	Author
Hyalorostratum	brunneisporum	Raja & Shearer
Class	Order	Family
Sordariomycetes	Basal to Diaporthales	Inc. sed.

Genbank ID: HM191719 MycoBank ID: 518893

Synonymy:

Description

Habit:

On submerged woody debris.

Ascomata:

Ascomata 500–620 × 200–290 µm, immersed, scattered, venter globose to subglobose and rounded at the base, membranous, reddish to light brown, ostiolate.

Peridium:

Peridium ca. 20–27 µm wide, composed of two layers; outer layer of dark brown pseudoparenchymatic cells ca. 7–9 × 2–3 µm, and inner layer of hyaline, flattened cells ca. 5–10 µm long.

Beak:

Neck erumpent, long, hyaline, periphysate 220–235 × 55–60 µm, covered with a tomentum of hyaline, filamentous hairs ca 2-3 × 5–7 µm.

Hamathecium:

Pseudoparaphyses numerous, extending into the ostiole, hyaline, septate, filamentous, broader at the base than at the apex, 160–170 × 2–3 at base.

Ascus:

Asci 185–240 × 10–20 µm, (mean = 210 × 15 µm, n = 25), unitunicate, cylindrical, thick-walled, rounded at the apex and tapering towards the base, pedicellate extending in water to ca. 350–400 µm in length, with a large, bipartite apical apparatus ca. 7 µm long and 3 µm wide; apex of the apical ring covered with gelatinous material; ring staining blue in aqueous nigrosin, containing eight overlapping, uniseriate ascospores; ascospores shot forcefully through the apical ring when the ascus extends in water.

Ascospore:

Ascospores 22–32 × 9–13 µm (mean = 25 × 11 µm, n = 50), ellipsoidal to reniform, 1-septate; septum darkened with age, hyaline when young becoming dark brown when mature , biguttulate to multiguttulate, with or without a gelatinous sheath.

Sheath:

Sheath, when present, extending about ca. 2–3 µm from the ascospore wall; surrounding the entire ascospore.

Appendage:

None observed.

Culture:

Anamorph:

None observed.

Other info

Type & Location:

USA. ALASKA: Headquarters Lake, Kenai Wildlife Refuge, Soldotna, 60˚27.806N, 151˚04.260W, on submerged woody debris, 5 September 2004, Wendy and John Witmer, A573-1 (HOLOTYPE, ILL).

Other Specimens:

USA. New Hampshire, Hubbard Brook Forest stream, on submerged woody debris, 10 September 2008, Rosalind Lowen, A573-2.

Substratum:

Submerged woody debris.

Habitat:

Lentic, Lotic

Distribution:

USA: AK, NH.

Pertinent Literature:

Raja HA, Miller AN, and Shearer CA. 2010. Mycosphere 1(4), 275–288.

Comments:

Additional Pictures

Sheath on young ascospores.
Ascus apical ring.
Extended ascus apex.
Ascus.
Young ascospore.
Ascus apical ring and separated ascus apex.
Ascospore discharge.
Paraphyses.
Developing ascus.
Asci in various stages of development and discharge.
Ascus apical ring stained with aqueous nigrosin.

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