Freshwater Ascomycetes - Species Monograph
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| Genus |
Species |
Author |
| Pseudohalonectria |
longirostrum |
C.A. Shearer |
| Class |
Order |
Family |
| Sordariomycetes |
Inc. sed. |
Magnaporthaceae |
|
| Synonymy: |
|
Description
|
| Habit: |
Saprobic, ascomata immersed or partially immersed in submerged, dead woody debris. |
|
| Ascomata: |
Ascomata 178-396 x 267-396 µm, on wood immersed or partially immersed , bright yellow, becoming brownish yellow, rostrate; venter globose to flattened globose, membranous. |
|
| Peridium: |
Peridium membranous, of textura angularis of very small-sized cells in face view, outer cells darkened yellow, inner cells pale yellow, pseudoparenchymatic. |
|
| Beak: |
Beaks 1683-3712 x 118-168 µm, very long, cylindrical, comprising parallel hyphae terminating in enlarged knob-like cells and covered with patches of long, hypha-like hairs, golden brown at base, pale yellow at the apex, periphysate. |
|
| Hamathecium: |
Paraphyses 144-240 x 7.2-9.6 µm, longer than asci, acuminate, 1- to 4- septate, attached to ascogenous hyphae. |
|
| Ascus: |
Asci 94-120 x 8.4-12 µm, cylindrical, straight or sigmoidal, containing eight ascospores in a single fascicle, with IKI-negative thimble-shaped apical apparatus, 3-5 x 2 µm, short stalked, separating from ascogenous hyphae at basal septum of ascus prior to ascospore discharge, and lying free in venter cavity. |
|
| Ascospore: |
Ascospores 84-105.6 x 3.0-4.0 µm, hyaline to pale yellow, yellow to orange in mass, 4- to 8- septate, filiform, or sigmoid , cells filled with lipid. |
|
| Sheath: |
None observed. |
|
| Appendage: |
None observed. |
|
| Culture: |
ATCC 52674. Colonies on cornmeal agar floccose, mostly immersed, hyaline at first, becoming intensely bright yellow; older regions of colony darkening, yellow pigment diffusing into the medium, colony reverse intensely yellow. colony margin regular |
| Anamorph: |
None observed. |
|
Other info
|
| Type & Location: |
PANAMA. Barro Colorado Island: Shannon Creek. A dried culture on alfalfa stems, isolated from a twig. CA Shearer, Mar 1981, CS-656-1, NY. |
| Other Specimens: |
|
| Substratum: |
Wood |
| Habitat: |
Lotic |
| Distribution: |
Panama |
| Pertinent Literature: |
C.A. Shearer. 1989. Pseudohalonectria (Lasiosphaeriaceae), an antagonistic genus from wood in freshwater. Canadian Journal of Botany 67: 1944-1955. |
| Comments: |
Formed soft-rot cavities on balsa and beechwood in this study, and on ash and cottonwood in another study. |
Additional Pictures
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Ascospore
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Ascus 2
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