T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Tricholoma terreum (Grey Knight) .

Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Agaricales
Family: Tricholomataceae
Genus: Tricholoma
Species: T. terreum
Binomial name: Tricholoma terreum
Synonyms: Agaricus terreum, Tricholoma myomyces
Common: names: Grey Knight, Dirty tricholoma

Tricholoma terreum is a grey-capped mushroom of the large genus Tricholoma. It is very common in New Zealand in radiata pine plantation forests and wherever pines are found from late summer until late autumn particularly in sheltered areas where the soil is damp.
It was historically regarded as edible but recent research work in China showed that this species is toxic and should not be eaten (Yin et al. 2014, 2015; http://www.first-nature.com/fungi/tricholoma-terreum.php) because it can result in rhabdomyolysis - the breakdown of muscle tissue that leads to the release of the protein myoglobin into the bloodstream and subsequent damage to the kidneys. Symptoms are muscle pain, especially in the shoulders, thighs or lower back, muscle weakness or trouble moving the arms or legs. abdominal pain, nausea or vomiting, fever, rapid heart rate, confusion, dehydration, lack of consciousness.

Tricholoma terreum caps are up to 10 cm in diameter, light to mid grey and have a dry felt-like surface when dry and may split as the cap expands. The flesh is white. Caps are bell-shaped at first, becoming umbonate.
The gills are white to a pale grey and they are widely spaced.
The pure white, long, smooth, cylindrical stem can be up to 8 cm tall. The stem has no ring on it. It occurs late summer to autumn in large groups on calcareous soils in coniferous and occasionally deciduous woodland.

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/