Candlesnuff fungusXylaria hypoxylon

The candlesnuff fungus (Xylaria hypoxylon), also called carbon antlers, looks like the wick of a snuffed-out candle or a tiny set of antlers. Thin, tough spikes 3 to 5 cm tall poke out of rotting stumps and logs, black and velvety at the base and white, as if dusted with flour, at the tips. It's an ascomycete with no cap or gills, and it isn't edible.

How do you identify candlesnuff fungus? The fruit body, called a stroma, is tough and springy, 3 to 5 cm tall, occasionally 8 cm, and only 2 to 8 mm thick. It can be a simple spike, but most are flattened and forked at the top like antlers. The white powder on the tips is a coat of asexual spores. In autumn the tips are white; by winter, as the sexual spores ripen inside, the whole stroma turns black and becomes finely bumpy. It grows in groups and tufts, always from wood, never from soil.

Where does it grow? On dead broadleaved wood: rotting stumps, logs and fallen branches of oak, beech and many other trees, occasionally on pine stumps. It's one of the last fungi to move into rotting wood, after honey fungus and sulphur tuft. It's very common. It can be found all year, though it's most noticeable from autumn through the winter, when its white tips stand out.

Is candlesnuff fungus poisonous? It isn't edible: it's thin and tough, and there's nothing to eat. We found no reports of poisoning, but that doesn't make it food. Unusual compounds isolated from it have shown effects on cells in lab tests, but there's no evidence of any health benefit.

What can you mistake it for? Dead man's fingers (Xylaria polymorpha) is far thicker, 1 to 3 cm wide, black and unbranched, at the base of stumps. Dead moll's fingers (X. longipes) has a swollen head on a narrow stalk. Beechmast candlesnuff (X. carpophila) is thread-thin and grows only on fallen beech nut cases in the leaf litter, so brush the litter aside to check. Yellow stagshorn has the same antler shape but is bright orange-yellow, greasy and rubbery, and grows on conifer stumps. Coral fungi such as grey coral and white spindles grow from soil or leaf litter and are pale and brittle, with no black base.

The candlesnuff fungus faintly glows in the dark, but so weakly that it only shows up on a long-exposure photograph taken in total darkness. It shares a black spore print with its relative in the same order, King Alfred's cakes.