a germ pore. Another potential edible lookalike is the "velvet shank", Flammulina velutipes. This species has gills that are white to pale yellow, a white spore print, and spores that are elliptical, smooth, and measure 6.5–9 by 2.5–4 µm. A rough resemblance has also been noted with the edible Hypholoma capnoides, the 'magic' mushroom Psilocybe subaeruginosa, as well as Conocybe filaris, another poisonous amatoxin-containing species. Habitat and distribution Galerina marginata is a saprobic fungus, obtaining nutrients by breaking down organic matter. It is known to have most of the major classes of secreted enzymes that dissolve plant cell wall polysaccharides, and has been used as a model saprobe in recent studies of ectomycorrhizal fungi. Because of its variety of enzymes capable of breaking down wood and other lignocellulosic materials, the Department of Energy Joint Genome Institute (JGI) is currently sequencing its genome. The fungus is typically reported to grow on or near the wood of conifers, although it has been observed to grow on hardwoods as well. Fruit bodies may grow solitarily, but more typically in groups or small clusters, and appear in the summer to autumn. Sometimes, they may grow on buried wood and thus appear to be growing on soil. Galerina marginata is widely distributed throughout the Northern Hemisphere, found in North America, Europe, Japan, Iran, continental Asia, and the Caucasus. In North America, it has been collected as far north as the boreal forest of Canada and subarctic and arctic habitats in Labrador, and south to Jalisco, Mexico. It is also found in Australia. Toxicity The toxins found in Galerina marginata are known as amatoxins. Amatoxins belong to a family of bicyclic octapeptide derivatives composed of an amino acid ring bridged by a sulfur atom and characterized by differences in their side groups; these compounds are responsible for more than 90% of fatal mushroom poisonings in humans. The amatoxins inhibit the enzyme RNA polymerase II, which copies the genetic code of DNA into messenger RNA molecules. The toxin naturally accumulates in liver cells, and the ensuing disruption of metabolism accounts for the severe liver dysfunction cause by amatoxins. Amatoxins also lead to kidney failure because, as the kidneys attempt to filter out poison, it damages the convoluted tubules and reenters the blood to recirculate and cause more damage. Initial symptoms after ingestion include severe abdominal pain, vomiting, and diarrhea which may last for six to nine hours.