Freshwater Ascomycetes - Species Monograph
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| Genus |
Species |
Author |
| Arnium |
apiculatum |
(Griffiths) Lundq. |
| Class |
Order |
Family |
| Sordariomycetes |
Sordariales |
Tripterosporaceae |
|
| Synonymy: |
|
Description
|
| Habit: |
Ascomata saprobic on wood, superficial, scattered or aggregated into small clusters. |
|
| Ascomata: |
Ascomata pyriform to subglobose, ostiolate 0.4-1.3 x 0.2-0.5 mm, covered with brown, thick-walled, straight or slightly curved, 0-1 septate hairs, 25-115 x 10-15 µm, hairs more numerous in the neck region, with subhyaline to brown flexuose hyphae at the base. |
|
| Peridium: |
Peridium 2.5-15 µm diameter wide, membranous, hyaline to greyish brown, semitransparent except for the dark brown opaque neck; peridial cells angular, pseudoparenchymatous, thin-walled. |
|
| Beak: |
Beaks 200-550 x 150-250 µm, cylindrical to conical, periphysate, positively phototropic. |
|
| Hamathecium: |
Paraphyses hyaline, filiform, thin-walled, septate, often longer than and mixed with the asci. |
|
| Ascus: |
Asci 150-250 x 15-50 µm, eight-spored, unitunicate, cylindrical, narrowed and somewhat rounded at the apices, tapering to a slender stipe 50-100 µm long, non-amyloid, apical apparatus a cylinder with slightly concave sides 7-21x 4-9 µm, thicker discharged, upper portion of the ascus rupturing from the basal portion along a predetermined circumcissile line. |
|
| Ascospore: |
Ascospores 30-35 x 17-23 µm, obliquely uniseriate, sometimes biseriate, broadly ellipsoidal, hyaline with conspicuous oil droplets when immature, becoming dark brown and 1-septate at maturity, ornamented with small rounded warts but appearing smooth by LM; conical processes covering germ spores at both ends, 2.3-7 µm long. |
|
| Sheath: |
Absent. |
|
| Appendage: |
Absent. |
|
| Culture: |
Colonies on half-strength EmersonÕs yeast, peptone, soluble starch agar floccose, white, turning grey to blackish. |
| Anamorph: |
Not seen. |
|
Other info
|
| Type & Location: |
British Isles: England: S. Devon, Mamhead, on dead Heracleum sphondylium stems, 1 September 1978, M.B. & J.P. Ellis (IMI 232650) |
| Other Specimens: |
U.S.A.: Illinois: Vermilion Co., Jordon Creek, on submerged Equisetum sp., 29 May 1978, C.A. Shearer J4-1, Ills, IMI 238683. |
| Substratum: |
Submerged Equisetum sp. |
| Habitat: |
lotic, small creek |
| Distribution: |
Britain and United States |
| Pertinent Literature: |
Shearer, C.A. , D.L. Hawksworth and S. Von Bodman. 1980. Arnium apiculatum (Griffiths) Lundq. Mycotaxon 11: 165-172. |
| Comments: |
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Additional Pictures
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Ascus1
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Ascus2
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Ascospore1
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Ascospores2
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