Xylaria hypoxylon is a small club-like fungus found scattered or gregariously clustered on rotting wood.  Commonly known as the Candle-snuff or Stag’s Horn fungus, Xylaria hypoxylon is found throughout North America and Europe, and may be encountered year round in California, although its small size makes this particular fungus very easy to overlook.

Xylaria hypoxylon, or Candle-snuff fungus

Xylaria Hypoxylon can appear slightly different depending on what stage the observer finds it.  It may range in color from white to black, the white form being more readily discernible against the dark forest floor. This difference in color is because this species of fungus engages in both sexual and asexual reproduction.  The primary fruiting bodies are black at the base, thin, wiry and branched with white tips. The white powdery tips are masses of asexual spores called conidia. The spores are produced inside microscopic tubules called asci.  These asci are then bundled into perithecia, small nodules, which appear as black spots eventually turning the fungus black.

Xylaria hypoxylon

Xylaria hypoxylon grows 2-8 cm high and 3-5 mm wide, and may be scattered or clustered on rotting wood, and especially favors oak and tan-oak in the fall and winter in northern California.  Its growth habit is erect, cylindrical or narrowly club-like when young, but as the fungus matures it usually becomes sparsely branched or forked at the tip, although occasionally lacks branches.

Xylaria hypoxylon occasionally is observed in a simple unbranched form

Candle-snuff fungus is not specifically toxic, but its tough texture renders this species inedible.

This is expected to be the last of our Mushroom Monday posts for a while, to make room for more updates on the orchard and gardens that are coming alive with the warmer weather, and now screaming for our undivided attention!  It’s been a lot of fun discovering the numerous species of fungi lurking here this winter, and it was an exceptional year as a result of all our rain.  Next fall, when the rains return in earnest, we will revive our ‘Mushroom Monday’ posts again.  In the meantime, back to the gardens!