Taisha is the author of today’s entry. She writes:
Today’s image is of the fungus Xylaria polymorpha, or, as its commonly refered to, dead man’s fingers. This photo was taken by Marianne (aka marcella2/tovje@Flickr) in 2006. Thanks Marianne, for the photo!
This saprotrophic fungus is widely distributed in deciduous forests of North America and Europe. The mycelium of Xylaria polymorpha (Xylariaceae) secretes a mixture of extracellular digestive enzymes on the woody material on which it grows, then absorbs the digested products for fuel to grow and reproduce. Brown to dark grey fruiting bodies arise in the spring. The fruiting bodies will emerge in groups resembling fingers or a hand and darken with age, hence the common name. Within the fruiting bodies are the perithecia, where spores are produced within the asci. The fruiting bodies may persist for several months, releasing the ascospores over time in the autumn or early winter.
Xylaria polymorphya is often used for spalting wood. Spalting is the colouration of wood through fungal colonization. This effect is valued by woodworkers for the aesthetic appeal and uniqueness. In recent times, spalting has been induced by the inoculation of fungi on wood. There are three main types of spalting: 1) bleaching (caused by white rot fungi); 2) pigmentation (caused by the coloured mycelium of some fungi); and 3) zone lines (caused by the formation of a barrier by one fungus to protect its resources from another, or delineate individuals from the same isolate). Xylaria polymorpha creates zone lines by producing melanin-type pigments. These blackish pigments act as a protective barrier, surrounding the fungal community and thereby blocking water exchange within the wood substrate (see: Robinson S.C., et al. 2009. Effects of substrate on laboratory spalting of sugar maple. Holzforschung. 63(4): 491, or, Tudor, D.et al. 2012. The influence of moisture content variation on fungal pigment in spalted wood. AMB Express. 2:69).
Botany resource link (added by Daniel): Botanical Accuracy, where “botanical mistakes in commercial and public venues and products are showcased and corrected”. Some very interesting stories and prominent mistakes, all documented by Dr. Lena Struwe and guest posters. Discovered via Graham Rice’s Transatlantic Gardener weblog.