Freshwater Ascomycetes - Species Monograph
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| Genus |
Species |
Author |
| Jahnula |
bipileata |
Raja & Shearer |
| Class |
Order |
Family |
| Dothideomycetes |
Jahnulales |
Inc. sed. |
Genbank ID:
435390
MycoBank ID:
501330
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| Synonymy: |
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Description
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| Habit: |
Ascomata on submerged wood. |
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| Ascomata: |
Ascomata on wood 395–400 x 200–205 µm, black translucent, membranous, subglobose to obpyriform, ostiolate, superficial with partially immersed base, upright to slightly horizontal, scattered, connected to the substrate by broad, brown, septate, superficial stoloniferous hyphae. |
|
| Peridium: |
Peridium 20–30 µm thick, in longitudinal section composed of 3–4 cell layers; inner layer of laterally compressed, hyaline to subhyaline, isodiametric cells, outer layer of large, moderately thick-walled, globose to angular cells 30–34 x 20–24 µm. |
|
| Beak: |
Neck 100–150 x 70–85 µm, pale brown, central; wall of the neck composed of short outwardly) diverging globose to cylindrical cells. |
|
| Hamathecium: |
Pseudoparaphyses 2–3 µm wide, septate, slightly constricted at the septa, hyaline, filamentous, branching and anastomosing above the asci. |
|
| Ascus: |
Asci 170–220 x 10–17 µm (mean= 197 x 15 µm, n=20), basal, fissitunicate, cylindrical, pedicellate, with or without an apical chamber; endoascus extending to 2 x the length of the ectoascus, with eight, overlapping uniseriate ascospores. |
|
| Ascospore: |
Ascospores 25–30 x 9–10 µm (mean= 29 x 10 µm, n= 50), broadly ellipsoidal to fusiform, dark brown, one-septate, slightly constricted at the septa, upper cell slightly broader and more apiculate than the lower cell, rough walled in an irregularly striated pa, with hyaline caps at both apices, up to 2 x 2–3 µm. |
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| Sheath: |
None observed. |
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| Appendage: |
None observed. |
|
| Culture: |
Ascospores 25–30 x 9–10 µm (mean= 29 x 10 µm, n= 50), broadly ellipsoidal to fusiform, dark brown, one-septate, slightly constricted at the septa, upper cell slightly broader and more apiculate than the lower cell, rough walled in an irregularly striated pa, with hyaline caps at both apices, up to 2 x 2–3 µm, lacking a sheath. |
| Anamorph: |
None observed. |
|
Other info
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| Type & Location: |
USA. FLORIDA: Appalachicola National Forest, swampy area of Whitehead Lake, 30°24'07''N, 84°48'12''W, UTM Zone 16 711030mE, 3365373mN, water temperature 29 C, pH 7.5, on submerged, decorticated wood, 13 Jul 2004, HAR and CB, F49-1 (ILL). HOLOTYPE. |
| Other Specimens: |
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| Substratum: |
Wood. |
| Habitat: |
Swamp. |
| Distribution: |
USA.(Florida) |
| Pertinent Literature: |
Raja, H.A. and C.A. Shearer. 2006. Jahnula species from North and Central America, including three new species. Mycologia 98: 319–332. |
| Comments: |
The long, cylindrical neck is distinctive and composed of globose to elongated cells that are directed outwards. The ascospores of J. bipileata are irregularly striated, rough-walled and possess a hyaline cap at the ends of the ascospore apices, features not observed in J. aquatica.
The hyaline caps on the ascospore apices of J. bipileata do not cover the germ pores; germination occurs from the lateral walls of the ascospores. |
Additional Pictures
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Rough-walled ascospore.
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Habit
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Germinating Ascospores
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Apex of Endoascus
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Centrum
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Broad Hyphae
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Ascus
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Endoascus Apical Chamber
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