Freshwater Ascomycetes - Species Monograph

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Genus	Species	Author
Jahnula	rostrata	Raja & Shearer
Class	Order	Family
Dothideomycetes	Jahnulales

Genbank ID: 435396 MycoBank ID: 501331

Synonymy:

Description

Habit:

Scattered, superficial on wood.

Ascomata:

Ascomata 207–264 x 147–150 µm, hyaline and translucent when young becoming translucent brown to black at maturity, globose to subglobose, solitary, scattered, superficial on wood, connected by stoloniferous hyphae ca. 15–19 µm wide, ostiolate, papillate

Peridium:

Peridium 36–38 µm wide, in longitudinal section 3–4 cell layers wide, innermost layer of hyaline cells compressed laterally, outermost layer of large, moderately thick-walled, isodiametric cells.

Beak:

Neck 38–40 x 30–32 µm, composed of subglobose cells diverging away from the ostiole; periphyses not observed.

Hamathecium:

Pseudoparaphyses 3–4 µm wide, septate, hyaline, anastomosing above the asci.

Ascus:

Asci 152–190 x 32–40 µm, basal, fissitunicate, clavate, short pedicellate, with an apical chamber and eight, overlapping biseriate ascospores.

Ascospore:

Ascospores 32–45 x 12–15 µm, ellipsoidal or broadly fusiform, dark brown, one-septate, slightly constricted at the septum, upper cell of ascospore broader than lower cell, rough walled in an irregularly striated pattern, multiguttulate.

Sheath:

Thin gelatinous sheath present.

Appendage:

None observed.

Culture:

Anamorph:

None observed.

Other info

Type & Location:

USA. FLORIDA: Ocala National Forest, Lake George, 29°13'41''N, 81°35'14''W, UTM Zone 17, 442930mE, 323395mN, water temperature 38 C, pH 6.7, on submerged, decorticated wood, 16 July 2004, HAR and CB, F4-1. (ILL). HOLOTYPE.

Other Specimens:

FLORIDA: Appalachicola National Forest, Big Gully Creek, 30°15'00''N, 85°10'54''W, UTM Zone 16, 671740mE, 3347836mN, water temperature 27 C, pH 6.6, on submerged, decorticated wood, 12 July 2004, HAR and CB, F4-2.

Substratum:

Decorticated woody debris.

Habitat:

Lentic, lotic.

Distribution:

USA: Florida

Pertinent Literature:

Raja and Shearer 2006

Comments:

Additional Pictures

Rough-walled ascospore.
Fissitunicate ascospore discharge.
Fissitunicate ascospore discharge.
Empty endoasci.
Endoascus apex.
Empty endoascus apex.
Wide hyphae attached to an ascoma.

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