Freshwater Ascomycetes - Species Monograph
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| Genus |
Species |
Author |
| Phaeosphaeria |
caricis |
(Schroeter) Leuchtmann |
| Class |
Order |
Family |
| Dothideomycetes |
Pleosporales |
Phaeosphaeriaceae |
|
| Synonymy: |
Basionym = Leptosphaeria caricis Schroeter, Jahresb. Schles. Ges. Vaterl. Cult. 58: 75. 1880.
=Leptosphaeria nardi var. dubiosa Mouton, Bull. Soc. Roy. Bot. Belgique 26: 177. 1887
Basionym = Leptosphaeria dubiosa (Mouton) Oudemanns, Enum. Syst. Fung. 1:981. 1919.
=Phaeosphaeria punctillum (Rehm) L. Holm, Symb. Bot. Upsal. 149(3): 125. 1957.
Basionym = Leptosphaeria punctillum Rehm, Ann. Mycol. 10: 356. 1912.
= Leptosphaeria typhiseda Petrak, Hedwigia 65: 220. 1925, non L.typhiseda Sacc. & Berlese, Rev. Mycol. Toulouse 8: 33. 1886.
= Leptosphaeria petrakii Sacc., Ann. Mycol. 12: 287. 1914. |
Description
|
| Habit: |
Ascomata immersed in stems of grasses. |
|
| Ascomata: |
Ascomata 105–148 x 98–129 µm, immersed, scattered, globose, brown. Beak 20–25 x 22–26 µm, papillate, central, terete, light brown to hyaline at the apex, periphysate. |
|
| Peridium: |
Peridium 8–14 µm thick, composed of 2–4 layers of pseudoparenchymatic cells, of textura angularis in surface and longitudinal view, wall thickened and darker toward outside, at times some cells appearing as rectangular, cells 6–12 x 4–6 µm. |
|
| Beak: |
Beak 20–25 x 22–26 µm, papillate, central, terete, light brown to hyaline at the apex, periphysate. |
|
| Hamathecium: |
Hamathecium of cellular pseudoparaphyses, 2–4 µm wide, slightly constricted at septa, somewhat uniform in width, with gel coating that does not stain with India ink. |
|
| Ascus: |
Asci 70–86 x 12–15.5 µm, fissitunicate, cylindrical, numerous, filling the entire venter, fasciculate, wide directly above the hoof-shaped stipe; with thick apex and small ocular chamber, with 8 overlapping obliquely tetraseriate ascospores. |
|
| Ascospore: |
Ascospores (32-) 34–39 (-46) x 4–6 µm, narrowly fusiform, with one end cell narrower than the other, straight or slightly curved, occasionally sigmoid, 5-septate, constricted or not at first septum, fourth cell slightly enlarged or not, central cells mostly longer than wide, light yellow individually, yellowish brown in mass when in asci, at times minutely granular (clearly seen in 5% KOH), smooth, with a gelatinous sheath not staining in India ink, 2.5–4.5 µm thick. |
|
| Sheath: |
Sheath gelatinous, not staining in India ink, 2.5–4.5 µm thick. |
|
| Appendage: |
Not observed. |
|
| Culture: |
|
| Anamorph: |
Not observed. |
|
Other info
|
| Type & Location: |
See Shoemaker & BabcocK 1989. |
| Other Specimens: |
Crystal Lake. UTM Zone 16, 297618mE, 5097887mN, 46°00.280N, 89°36.835'W, on submerged dead grass stem, 27 June 1995, PMF P7-7-x (ILLS 54049). |
| Substratum: |
This fungus occurred in Crystal Lake, WI, during the month of May in 1996 on submerged partially decomposed blades and leaves of Poa wolfii Scribn (Fallah 199). This species also has been reported on other substrata such as Carex sp., Juncus sp., Luzula n |
| Habitat: |
Lentic. |
| Distribution: |
North America (Wisconsin), Eastern Europe. |
| Pertinent Literature: |
Shoemaker & Babcock 1989; Fallah 1999. |
| Comments: |
Shoemaker & Babcock (1989) introduced the subgenus Spathispora under Phaeosphaeria for those species that have 5 or more septate ascospores with cylindrical apical portion and tapered basal portion and that are smooth or echinulate and with or without a sheath. The specimen described here has features similar to those described for P. caricis (Shoemaker and Babcock, 1989; Leuchtmann 1984). An interesting feature in P. caricis is the hyaline tip of the beak which can be seen clearly in fresh material or when dried specimens are hydrated in water. Sectioned ascomata tend to be dark brown throughout due to the embedding procedures. A small ocular chamber was prominent in asci. This is especially visible when asci are mounted in 5 % KOH (Funk and Shoemaker 1967). The small ascospore granules which Shoemaker and Babcock (1989) describe can be seen mostly when ascospores are mounted in distilled water and/or 5% KOH. Specimens that were fixed in lactic acid with Azure A did not give similar results. Thus the presence or absence of these granules may not be of significant taxonomic value. |
Additional Pictures
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Ascomal bar = 50 µm; other pictures, bar = 25 µm.
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