Phylum: Ascomycota - Class: Sordariomycetes - Order: Xylariales - Family: Xylariaceae
Distribution - Taxonomic History - Etymology - Identification - Reference Sources
Hypoxylon fuscum, commonly called the Hazel Woodwart, appears throughout the year but actively distributes its spores during autumn and early winter. This wood-rotting fungus is one of the pyromycetes or flask fungi.
A common species in Britain and Ireland, Hypoxylon fuscum is found also throughout mainland Europe and in many parts of North America.
The scientific name Sphaeria fusca was given to this ascomycetous fungus in 1794 by Christiaan Hendrick Persoon, but its currently accepted name Hypoxylon fragiforme dates from 1849, when Swedish mycologist Elias Magnus Fries transferred Hazel Woodwart to the genus Hypoxylon.
The many synonyms of Hypoxylon fusca include Sphaeria fusca Pers., Cladotrichum fuscum (Pers.) Sacc., Hypoxylon glomerulatum Bull., Sphaeria coryli DC.. & Lam., and Sphaeria tuberculosa Bolton.
The genus name hypoxylon comes from hypo- meaning beneath (or less than) and -xylon meaning wood. The specific epithet fuscum comes from Latin and means dark or dusky.
![]() |
DescriptionStroma (plural stromata) - the name given to the communal fruitbody of an ascomycete fungi - hemispherical or hemi-ellipsoidal, 2 to 5mm in diameter and 0.5-2mm tall, often coalescing; initially creamy-white to honey-coloured, becoming dark vinaceous brown at maturity before blackening when old. |
![]() |
ConidiaAt the anamorph (asexual reproduction) stage - especially when the stromata are just forming, but it can occur at any stage - the stromata surfaces become powdery and buff to honey-coloured as sub-spherical conidiospores 3.5-5.5 x 2-3.5µm develop on the surface. |
AscosporesElongated ellipsoidal to fusiform with sharply rounded ends, sometimes slightly allantoid (sausage shaped to bean shaped), smooth, 11-16 x 5-8µm. Spore printBrown. AsciTypically 105-170 x 7-10µm, with eight spores per ascus; tips amyloid. |
|
Odour/taste |
Not distinctive. |
Habitat & Ecological role |
Saprobic, on fallen branches and dead standing broad-leaf trees, most often Hazel. |
Season |
Throughout the year, but producing ascospores in autumn and early winter. |
Similar species |
Hypoxylon fragiforme is nearly always found on dead Beech wood. |
, Pat O'Reilly 2016.
Dennis, R.W.G. (1981). British Ascomycetes; Lubrecht & Cramer; ISBN: 3768205525.
Breitenbach, J. & Kränzlin, F. (1984). Fungi of Switzerland. Volume 1: Ascomycetes. Verlag Mykologia: Luzern, Switzerland.
Medardi, G. (2006). Ascomiceti d'Italia. Centro Studi Micologici: Trento.
Dictionary of the Fungi; Paul M. Kirk, Paul F. Cannon, David W. Minter and J. A. Stalpers; CABI, 2008.
Please Help Us: If you have found this information interesting and useful, please consider helping to keep First Nature online by making a small donation towards the web hosting and internet costs.
Any donations over and above the essential running costs will help support the conservation work of Plantlife, the Rivers Trust and charitable botanic gardens - as do author royalties and publisher proceeds from books by Pat and Sue.