Genus Hypoxylon
Key to Taxa of Hypoxylon
Accepted Taxa
List of Names

Yu-Ming Ju
Michael J. Adams

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.
LECTOTYPE [selected by Ju and Rogers (1996)]: H. corrugatum (Fr.: Fr.) Fr. [= H. multiforme (Fr.: Fr.) Fr.]

= Hypoxylon section Epixylon Nitschke, Pyren. Germ., p. 42. 1867.
LECTOTYPE [selected by Ju and Rogers (1996)]: H. cohaerens (Pers.: Fr.) Fr.

= Hypoxylon section Marginatum Rick, BrotÚria, sÚr. Bot., 25: 22. 1931.
TYPE: H. marginatum (Schwein.) Berk. [º H. annulatum (Schwein.: Fr.) Mont.]

= Hypoxylon section Papillata J. H. Miller, Monogr. of the World Species of Hypoxylon, p. 45. 1961.
TYPE: H. multiforme (Fr.: Fr.) Fr.

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.

peritheciumA.JPG (9786 bytes)
Fig. 1

ostioleA.JPG (7867 bytes)
Fig. 2

perisporeA.JPG (8061 bytes)
Fig. 3