SECTION ANNULATA
| Hypoxylon section Annulata J. H.
Miller emend. Y.-M. Ju & J. D. Rogers, Monogr. of the World Species of Hypoxylon,
p. 86. 1961. Type: H. truncatum (Schwein.: Fr.) J. H. Miller = Hypoxylon
section Effusae Fr., Summa Veg. Scand. II, p. 384. 1849. = Hypoxylon section Epixylon Nitschke, Pyren. Germ., p. 42.
1867. = Hypoxylon section Marginatum Rick, Brotéria, sér. Bot.,
25: 22. 1931. = Hypoxylon section Papillata J. H. Miller, Monogr. of the
World Species of Hypoxylon, p. 45. 1961. |
|
| Stromata with surface usually blackened when mature, infrequently
colored. Carbonaceous stromatal layer discretely enclosing each perithecium (Fig. 1).
Ostioles always higher than the level of surrounding stromatal surface, encircled with an
annulate disc (Fig. 2) or with annulate disc lacking. Perispore, when dehiscing, with a
thickened area visible at the position of ca. 1/3 ascospore length on the same side as the
germ slit (Fig. 3). Formation of ostiolar discs can be classified into two major types: truncatum-type and bovei-type. Both types of ostiolar disc formation have a white palisade tissue layer which functions to separate the outermost stromatal tissue around the ostiole from the stromatal tissue beneath. It is noteworthy that members of section Annulata usually produce irregular black carbonaceous patches over the entire surface of colonies in culture. This characteristic may eventually be proven useful to determine whether a culture belongs to section Hypoxylon or section Annulata. |
 Fig. 1
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