Halorosellinia
oceanica
(S. Schatz) Whalley, E.B.G. Jones, K.D. Hyde & Læssøe
Sordariomycetes, Subclass Xylariomycetidae
Xylariales
Xylariaceae
Sexual morph: Pseudostromata 0.4-0.8 mm diam., seated on decorticated wood, occasionally embedded at the base, pulvinate to hemispherical, single, in clusters of up to 30 uni-peritheciate pseudostromata, linear to suborbicular, surface leathery in fresh material, at maturity black, generally with conspicuous ascomatal projections. In section pseudostromata comprising host cells filled with light brown fungal cells in the form of textura globulosa or amorphous black fungal material. Ascomata immersed in pseudostroma, subglobose to hemispherical, soft to leathery, black, ostioles papillate. Paraphyses 2-2.5 μm wide at the base, abundant, persistent, remotely septate. Peridium 25-35 μm wide, two layered, composed of an outer layer of cells of textura angularis and an inner layer of elongated cells. Asci 177-219 × 17-23 μm, eight-spored, cylindrical, unitunicate, subapical apparatus dark blue in Melzer’s reagent, tapering with a distinct apical rim, (4.7-)5.6-6.6 × 4.2-4.7 μm. Ascospores (17.9-)18.7-26(-28) × 7.5-13(-13.5) μm, uniseriate to obliquely uniseriate or partially biseriate at the upper end of the ascus, dark grey-olive to opaque brown, more or less inequilaterally ellipsoid, upper end broadly rounded, lower end slightly pointed, one-celled throughout ascospore development, bi-guttulate, wall smooth and relatively thick, without appendages or loosening perispore, germination slit usually clearly seen on the ventral side, straight, conspicuous, ½-¾ total length of spore. Asexual morph: undetermined.
Key references:
Li GJ, Hyde KD, Zhao EL, Hongsanan S, Abdel-Aziz FA, Abdel-Wahab MA, Alvarado P et al. (2016) Fungal diversity notes 253–366: taxonomic and phylogenetic contributions to fungal taxa. Fungal Diversity (**). DOI 10.1007/s13225-016-0366-9.
Li HJ, Lin YC, Wang L, Zhou SN, Vrijmeod LLP, Jones EBG. (2001) Metabolites of marine fungus Hypoxylon oceanicum (#326) from the South China. Sea. Acta Scientiarum Naturalium University Sunyatseni 40: 70.
Schatz S (1988) Hypoxylon oceanicum sp.nov. from mangroves. Mycotaxon. 33:413-418.
Schilingham G, Milne L, Williams DR, Carter GT. (1998) Cell wall active antifungal compounds produced by the marine fungus Hypoxylon oceanicum LL-15G256. II. Isolation and structure determination. Journal of Antibiotics 51: 303-316.
Smith GJD, Liew ECY, Hyde KD. (2003) The Xylariales: a monophyletic order containing 7 families. Fungal Diversity 13: 175-208.
Whalley AJS, Jones EBG, Hyde KD, Læssøe T. (2000) Halorosellinia gen. nov. to accommodate Hypoxylon oceanicum, a common mangrove species. Mycological Research 104: 368-374.
Key to species:
1. Ascomata soft to leathery, 4–0 ± 8 mm in diam., (17.9-)18.7-26(-28) × 7.5-13(-13.5) μm H. oceanica
- Ascomata carbonaceous, 1.5–2.5 × 0.9–1 mm, in diam., ascospores 24–36 × 10–15 µm H. rhizophorae
Image: Halorosellinia oceanica. (a) Surface of pseudostroma with masses of discharged spores above the ostiole. (b) Section of immersed ascoma in the pseudostroma. (c) Ascoma neck with periphyses. (d) Two-layered peridium, outer layer of cells of textura angularis, inner
layer of elongated cells. (e) Ascus with near-mature ascospores. (f) Mature ascus with subapical apparatus. (g) Ascospore dark brown with a longitudinal germ-slit. Scale bar: a=300 μm; b=100 μm; c, d, e, f=30 μm; g=10 μm. Photo reproduced with the permission of the National Taiwan Ocean University.